Editor's note: The following is an excerpt from Kimberly Guilfoyle's new book "Making the Case: How to Be Your Own Best Advocate" (Harper, May 26, 2015). Get it signed by Guilfoyle!

The examples of people's camaraderie and thoughtfulness are endless. The friends I have from childhood are definitely like family to me?extended sisters and brothers, aunts and uncles. So when I read or hear about toxic friendships, I'm sad for people who don't know what having loving friends is like. I don't believe in spending time with people who are harmful to me emotionally,mentally, spiritually, physically, or financially. I wish that young people, most of all, would learn to cut ties with those who make them feel bad about themselves or about the other people they love and care for. Continual, intentional, or snarky putdowns have no place in a healthy relationship.

Advocating for yourself in the context of friendship starts with choosing the right people to be part of your inner circle.

In my mind, friends should be patient, reliable, and consistent. I believe in their being steadfast so you can count on them. When they say they are going to be somewhere or do something, they follow through. They don't abandon you in social situations to be with people they perceive to be more important, and they especially don't abandon you when you are in need.

Friends should be unfailingly honest too. They should help you see yourself at times when you don't have objectivity. Although their reflections should be truthful, they should also be couched in kind, considerate, and caring language. My friend Dendy calls this a love sandwich. It's when you deliver constructive criticism in a palatable way by putting it between thoughtful statements. She practices this with friends and with her husband, Devin.

Certainly, friends should be trusted confidants. They should never betray confidences by spreading rumors, talking about you behind your back, or sharing whatever you told them in private with others. They especially shouldn't exploit you on social media, where their indiscretions can be far-reaching and permanent.

They should be fair and just advisers. They should listen to you as often, and with as much compassion, as you listen to them. They should also offer guidance they know will help a bad situation improve?not advice that only compounds your problems. And they shouldn't poison your relationships with others they perceive to be competing for your time (including the person you are dating or even your spouse).

I also believe that friends should be co-adventurers and your most ardent defenders. They should encourage you to step out of your comfort zone, to try new things that will help you grow and develop. They do not encourage you to try things that will damage your health, self-esteem, or bank account. They also have your back whenever you take those scary first steps toward meeting new challenges and goals.

Finally, friends should always make you feel like you are in good company. If you feel alone, used, sad, or anxious when you are with your friends, you are definitely in a toxic relationship and you need to get out.
In my mind, friends should be patient, reliable, and consistent. I believe in their being steadfast so you can count on them. When they say they are going to be somewhere or do something, they follow through. They don't abandon you in social situations to be with people they perceive to be more important, and they especially don't abandon you when you are in need.

Are you this type of friend to others? Are they this way with you? Friendship goes both ways. If you are being a good friend to someone who is not being a good friend to you, you have to disengage. And if you are the one not being a good friend, you need to think about why, then commit to changing your ways or commit to changing friends so your friendship is reciprocated and valued.

While many people know these rules to be true, few people know what to do when a friend isn't abiding by them. That's when common sense comes into play. Different situations may warrant different reactions. For instance, if a friend says offensive things to you or others on a regular basis to get a rise out of you or to jockey for a better position in the group, reverse peer pressure might be one way to make her aware of the problem and to get her to stop. All too often, silence makes you complicit in her bad behavior. If she is gossiping about another friend or she is being rude or disrespectful, then you and your other friends can collectively and directly let this person know that what she is saying is not okay with you. When she realizes that she can't sway others to participate in her guilty pleasures, she can either leave the group or rise to your standards. The choice is hers. In many ways, this kind of positive peer pressure advocates for her to mature and become a better person. I think you just learn to do this naturally as you get older. Your other friends don't even have to speak to you about the issue. You all just pick up on the cues and shut it down before it ever gets to be a big problem.

If a friend hurts you in some other way and it was an isolated incident, then by all means speak up. Address the situation. Let it be known that you didn't appreciate what happened and that you expect more from this person going forward. As with all forms of advocating, try to understand where she may have been coming from, and what might have caused her to behave in an otherwise uncharacteristic manner. Everyone deserves at least one pass.

If, however, you doubt the other person's judgment; if you find that she is well meaning but still gives you bad or inappropriate advice or she makes poor choices of her own, it's definitely time to unfriend this person. You know the old saying "Screw me once, shame on you. Screw me twice, shame on me." You have to take some responsibility for the situation and walk away. Don't play the victim. There is no need for histrionics or drama. Friendships are the perfect ground for discovering things about ourselves, including what we will and will not tolerate.

I truly believe that it's important to accept that we all mature at different rates, we all push boundaries more or less than others, and we are all competitive to varying degrees. Just move on knowing you took a valuable lesson away from the experience. Hopefully you won't make the same mistake again. If the first step of advocating for oneself is knowing yourself better so you can be clear about your needs in a situation you wish to improve, then recognize that the friendship?while disappointing in other ways?helped you do just that. It helped you discover the kind of company you do not want to keep. You and this friend are already headed down different paths so just continue on your way. To disengage from the friendship, stop hanging out, texting, or calling each other. There is no need to call them out or put them on the defensive. People outgrow friendships all the time. The friendships that are keepers are with people who have proved they share your values. You may not see the results of cutting ties with fair-weather friends right away, but sometimes when people reflect on lost friendships later in life they are in a better place to recognize and deal honestly with their own contribution to the breakup.

In retrospect, I realize that there were times in my life when my needs were so great?certainly after the loss of my mother and later my father, and at the time of my divorces?that the balance in some of my friendships weighed more in my favor. I might not have seen it at the time, but I certainly did when I was in a better place. In most instances, my friends remained patient and I was able to correct the imbalance, being there for them when they needed me. Interestingly enough, when two friends are going through a hard period at the same time, they can actually deepen their friendship. Helping others with their problems helps put yours in perspective and allows you to advocate for yourself and someone else simultaneously, often proving to yourself that you have a lot more inner resolve than you realize.

A special note for parents: modeling strong friendships is good for your grown children as well as your young children. There may be a time later in life when friends are all they have. If they don't know how to cultivate the right ones, they will be at a severe disadvantage. This is very likely why my dad taught me to love and value my friends. Kids witness competitive and toxic interactions between adults more often than they should. The best defense against this is to treat your own friends with respect, gentleness, and warmth.

Speaking of parents, my dad was the kind of man who was a friend to all. He believed in extending courtesy and humanity to everyone you meet?and an added dose of understanding and compassion if you sensed they were going through a difficult time. But he understood that there were different levels of friendship and that you have to set your expectations accordingly. There are people who are fun to hang out with; others whom you bond with intensely over a common goal, but little else; and those you click with on almost every level. The latter are your truest friends?people who go beyond the in vogue termsbesties and bffs. People who are there for you in times of both joy and need. People you care about deeply enough to be there for in return. You could meet them anywhere and under any circumstances. They could be neighbors or coworkers, classmates or total strangers who struck up a random conversation with you that led to years of cherished talks. My dad was always open to the prospect of friendship on any of these levels because he loved people, but he had a few rules of his own. One of them was you can't expect other people to be good caretakers of your personal business if you aren't a good custodian of that business yourself. He kept the details of his private life private. Those were reserved for his family and inner circle of friends. He believed in being smart about what you put out in the world for public consumption. If you tell anyone who will listen all about your problems, fears, or even your hopes and dreams without knowing their character, what their intent and motivation is for listening, or what they will do with that personal information, the responsibility for anything bad that happens is on you. He always advised us to pick and choose our friends wisely. A friend has to earn your trust and you must earn hers. He also taught us that you cultivate great friendships by being a great friend.

Purchase Guilfoyle's new book "Making the Case: How to Be Your Own Best Advocate" (Harper, May 26, 2015).