very different responses from different folks (which is cool of course)
I am a little more different (or 'picky'?)
I like to trade within same era
87-93 for similar
81-86 or 94-99 for similar, even crossing over
00-present for similar
I also like to trade baseball for baseball, and football/basketball for football/basketball (cross over ok)
I will bend on these if I need the card badly for certain of my collections.
If I get a blind proposal wtihout discussion for your 91 basketball for my 2015 baseball, I will likely decline
I also look at the type of card and player (oddball or sticker for oddball or sticker, HOF player for same) etc
maybe I am a little too rigid, but this general approach works for me
thanks, mark