I've talked about this before. When you agree to sign up for something (anything), show up and do what you said you were going to do. This is being impeccable with your word (for those of you familiar with the Four Agreements) and also just something a good friend will do. Or, to put it more bluntly, something reasonable that you should do no matter who you agree to do it for (family, strangers, acquaintances, etc.)

I think we all agree to things at times when we're busy and we honestly think we want to do them but when the time comes for it to happen... we just skip it.

This behavior not only makes us look bad, it puts others in bad positions, too. You'll never know how, perhaps a year down the road, you will see or talk with someone that remembered you because you failed to show up when you said you were going to. Is that the way you want to start a friendship?

It's always interesting to me how rivals can become friends. I don't think it's unusual, especially when you have two rivals, or competitors, at the top of their game. They both share a passion for one specific thing, and even though they may be competing against each other, they have this shared interest that looms large between them.

Bill Gates and Steve Jobs certainly had that kind of rivalry, but they respected each other. Eventually that respect turned toward friendship. I think theirs is a good example of how different people can add a different element of friendship to your life.

Gates says of Jobs: "He and I, in a sense, grew up together." They were close in age and "kind of naively optimistic and built big companies."

They were very aware of each other, they competed in the business world, and were rivals. And yet, they obviously respected one another. Gates said "The world rarely sees someone who has had the profound impact Steve has had, the effects of which will be felt for many generations to come. I will miss Steve immensely."

I love Twitter on Fridays because that's when the #FridayReads hashtag trends. I'm always on the lookout for new books that people love, which is one reason I ask you all to share your favorite books as well.

I like to alert you to books that can improve your friendships, too. Some of your favorites here are MWF Seeking BFF by Rachel Bertsche, and Toxic Friends by Susan Shapiro Barash. Did you know that you can write reviews on those books here? Let others know what you think.

But you'd be surprised at how many books that aren't "how to's" or even nonfiction works can teach you about friendship. For instance, I recently talked about The Four Agreements, and how you can apply those concepts to friendship.

And is there anything better than hearing about how real people (even when they're famous) deal with, think of, and handle friends? To that end, I've also suggested five great memoirs with strong lessons on friendship.

Many of you prefer to just read for enjoyment, and as if there's a lesson in there somewhere? Great. Most of all, though, you just want a good story. Well how about these ten novels that showcase friendship stories?

Sometimes a subject not specifically about friendship can also help you be a better friend. For example, these five books on happiness can help you be more content in life in general, and as a result you might want to figure out how to make your friendships happier or how to meet a wide variety of new people.

Don't forget to share your choices on Twitter, also.

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I don't think it's so much the end of a friendship that bothers us sometimes (because we realize there was a problem of some sort) but when a friendship ends and we just didn't see it coming. We ask ourselves all kinds of questions about what happened. Why? What did I do?

We might even wonder if we'll ever find another friend like them. And while sometimes friendships do end by surprise, I also think there are times when it's more common for friendships to end than others. Here are a few of those times.