1) When a friend advices me on something, I tend to ask why. Then I tend to think whether his reason is ocnvincing.
This is not so good. Advice represents also the friends' more general opinion about what I should do, which cannot be reduced to the reason he is giving.
I must take into account that my friend thinks so, regardless to his specific reason.
Note also that when we analyze the friends reasons, we go back to our own opinion....
2) Another reason for taking a friends advice as it is, is that the very opinion of a friend is informative even when we do not think so. Reality is not within our own opinion, but can be different from what we think.
3) Against advice. A problem with advice for personal life in general, is that life is complex, and advice must be compatible with one's life. Many times advice does not really take into account the advicee way of life, constraints, strategies etc.
See my post How different are you?
Ultimately, one got to be smart. There are no simple and clear technical rules