After being on both the giving and recieving end of many a rant, I've decided that there are too many bad mantras out there regarding how to talk to your friends about their problems. They are listed here. But let's start with a background:

Why do people talk about problems?
When I was 17, I would constantly, like, every other day, rant at my mom about some friends who I thought were holding me back. Mom would just kinda say nothing or "Oh." One day I wondered aloud, "Why do I keep talking about this?" I figured it was because I want to know that my words are geting through, and the examples I used truly do prove what these friends were doing. I told her this and she said "I agree! These people are bad for your progress!" And I was satisfied and felt no more need to tell the stories of being held down, for the most part.

What ranters want is either validation or an explanation of why they are wrong. We want our emotions to make sense, and if someone else explains that we are right or wrong, then we feel like we know it better. 

But we've been told a lot things about how to talk to our friends that are WRONG. So that you can avoid that advice, I have them listed here. Don't do any of these things.

1. Just listen and nod.
If I wanted that, I would talk to a brick wall. Er, a bobblehead maybe.

2. Assume you understand.
Example: Your friend Bob is mad at Sally for not driving him to a party, even though she promised three times.
Ask if you understand what he is mad about. "So, you're angry that she is not reliable?"
If you just assume that this is correct, you'll be talking to him about Sally's reliability. However, he may be concerned that Sally is avoiding him, or playing practical jokes. Asking questions is imperative; otherwise you (and your friend!) may never know what the problem really is.

3. Just tell them it's not that bad.
In the scheme of things, maybe it isn't that bad. But don't assume that it's ok.
Example: Bob is mad that Sally purposefully shot him in the eye with a BB gun.
BAD RESPONSE: "Oh, that's fine, I'm sure she was just trying to be funny, at least you have another eye."
PROPER RESPONSE: "WHAT THE FUCK?! Report that piece of crap!"
If you respond with the bad response, then Bob will feel like his emotions don't mean anything and are unfounded. Worse, he will consider that atrocious acts like shooting people in the eye are okay, and there's no reason why he shouldn't do it too, or back.

4. Just tell them that the other person is a big jerk.
This is what I see on all the time, especially on facebook. We do this because we like our friends and we think they deserve the best, and everyone who hurts them should be hurt back. Whatever problems they have need to be avenged. We also do this because we only know our friends side of the story.
Example: Bob is mad at Sally for inviting him to a rugby game, a sport he hates.
BAD (but typical) RESPONSE: "Wow, that is just really selfish. I mean, jeez, Sally isn't the only person in the world, why can't she think of your needs?"
WORSE RESPONSE: "You deserve better than this, Bob. I think you need to cut the chord."
BETTER RESPONSE: "You're mad at her for offering you something? Jesus, she was just trying to be nice, Bob."
If you respond with the bad response, Bob will become entitled and believe that everyone should treat him like royalty. If you respond with the worse response (and he takes your advice) he will soon end up with NO friends, and guess what? He'll eventually find a reason to hate you too.

5. Spout trite cliches.
We do this beause we think that we can simplify things by using short quotations. But they're stupid. Use EXAMPLES and ANECDOTES instead. They are less judgemental and at the same time much more useful.
Example: Bob wants to try running hurdles, but is concerned about hurting himself.
GOOD RESPONSE: "I ran hurdles for four years, and I never hurt myself. I saw lots of people get stress fractures and shin splints, but I never saw a single person get hurt doing hurdles. Even when you hit them, they just fall over."
When you respond with a cliche, it says that you didn't really think about it. It doesn't say if you would take that route yourself. Cliches do not consider the context at all, but true stories create their own context.

6. Give a premature verdict.
I've just outlined what kind of answers not to give, but sometimes you shouldn't give one at all. Just help your friend come to a conclusion.
Let's go back to the first example, where Sally didn't drive Bob to the party. You should ask Bob what he thinks his options are. Maybe now that he's put it into words, he has more clarity. Maybe he'll get over it, maybe he'll talk to Sally, maybe he'll not rely on Sally anymore, maybe he won't invite Sally out anymore, maybe he wants to cut off all contact. You could and should offer your opinion from what you've obersved, but make sure Bob knows what his options are first. You can tell him what you think of his plan.
Conclusion: Talking about your problems shouldn't be much different than a normal conversation. People do not want to be manipulated into feeling a certain way, and they certainly don't want to be lied to for their own protection. The best you can do is simply be HONEST!