I've assigned a grade for everything from about 1982 and older with football and 1980 or older in baseball. For cards after that, I only put a grade for anything less than NrMt or Ex-Mt.
To answer Schwitz, I've tried to grade the best I can according to guidelines I've seen here and there. I try to be strict, so that someone doesn't get a card and think, "That's not Ex at all! Ex, my left foot!" It also can be a starting point. A potential trade partner may not care that a card is "well loved," but for someone who condition is important, they can ask for more precise details.
Condition matters to me in some sets I'm trying to finish, mostly because the cards I already have are NrMt or Ex-Mt, such as 1986 Donruss baseball, 1982 Topps football and 1989 Topps football.
I love to trade! Check the top couple of paragraphs of my profile to see my general trading desires. If you're uncertain if I’ll take a certain trade, message me and we can figure out something.