What is the "right thing to do in these situations"?
"Right thing" is such an evil phrase. LOL. For me, if I think a friend is making a serious mistake...I can't sit by and say nothing. I mean I care about this person right?! However I am usually really cautious about how to word things. I usually try to ask as many questions as possible so I have a full picture of what's going on. And I try to really listen before I jump in. And I always try to preface it with, "This is what I am seeing in this situation." Followed by all sorts of comments starting with "In my experience". I think it's important to not get jumpy, even with a close friend.
How did they react?
Most good friends will thank you for your input, understand why you feel the way you do, and realize you have their best interest at heart. (There is a big difference between unsolicted advice and critical analysis of someone's life; ie. "Good christ how dumb can you be? Remember the last hairbrained idea you had!")
However, I have found most people are going to do what they want to. Advice or not. It might stall them, but for the most part you do have to live and let live. And you also have to be there for when perhaps things don't work out, but you also have to be there when your advice was wrong and you perhaps need to eat some of your words. It's all a part of the friendship process.
There was only one time in my life where I felt the advice I gave wasn't heeded and I needed to end the friendship as a result. Her bad choices, and constant whining about how terriable her life was, was too much of an emotional drain on me. And since I felt her choices were the absolute WRONG choices, our friendship had to end. I sometimes wonder if that was the right course of action--was I being too hard on her? Was I shunning her now? (Not to say I cut off all communication with her--I just made it known I didn't like the person she had become because of her choices).
Have you had friends give you unsolicited advice?
Yup.
How did you feel?
Depended on my friend, how it was said, and when it was said.
Honestly, when I was younger my attitude was usually, "thanks but no thanks". Because I was so different, and my situation so unique. Oh god, how I giggle. I realize now how much problems are universal. Some of the details may different, but the nuts and bolts usually boil down to the same age old dynamics. It's not easy--but I have been working on taking advice, even the unsolicited variety very seriously--and weighing it into my understanding of myself and my situations.
I sort of liken it to painting on a huge canvas. Sometimes you get so engrossed in your little section you can't see everything all around you. You get so wrapped up in one element that you fail to realize (usually) the insignifigance of what you are struggling with. Sometimes you need an outsider to tell you how big your canvas is, and where you should really be paying all your attention.
Ok that was a crap metaphor I realize, but it's the best I've got.