Basically, some things to think about regarding appearance:
1) Does appearance matter to you? When you read, do you want all your characters to be conventionally attractive? Relatable appearance-wise? Normal?
2) Would you prefer just a little description or lots? Obviously no one wants three pages of description of that character's looks, but do you require more than "green eyes, dark hair" or is that A-OK with you?
3) Is there an appearance you like more than others? Like, tall buff hairy dude vs. more delicate, long hair, etc. Will you refuse to read a story if a character looks like _______?
4) Anything else that bothers you/ that you love regarding appearance in slash?
My opinion (cuz I know you ALL WANT TO HEAR IT, OH YES YOU DO) is that slash focuses FAR too heavily on appearance. Seriously, every single story is "This guy was hot" or "That guy was hot". Well, we can't ALL be hot gay dudes, can we? I blame mostly the media for pounding it into our brains how important appearance is, when it's really not. Okay, I understand guys probably don't want to sleep with a guy who doesn't turn them on, but does everyone in slash have to be six-foot-two and ripped? Really? Like, can't anyone ever be average? Average is far more relatable. The guy can have good qualities and bad qualities. He has pretty eyes vs. overweight, nice hair vs. bad skin, etc. And that's another thing: chub. I would like to see a couple more guys who aren't either 80 lb. stringbeans or 180 lb. ripped gods.
Also, I hate the "this is totally a flaw guiz!" syndrome. Like how the scrawny emo kid always insists he's OMG SO UGLY when everyone in that story worships him and his perfect KAWAII looks. Author, you are not fooling ANYONE. No, really, you aren't.
Regarding description, I prefer something solid. I'm not going to dislike a story if it skimps on the physical description, but I love it when the author mentions something unique about that character's appearance beyond "blue eyes, blond hair". Like the shape of his nose. His big red ears. The cowlick at the back of his neck. The cleft in his chin. SOMETHING DIFFERENT to let me know what this character looks like. I never buy the "this guy was so hot" description either. HOW is he hot? ENLIGHTEN ME. And don't give me the whole "he looked like Taylor Lautner!" or "six pack, sexy eyes". What does that even MEAN? Trust me, not-so-hot guys can actually be really sexy if they play the part, and I want to read that.
I don't like the short/skinny/feminine trope just because I'm so sick of seeing it. A guy can be feminine without being short and skinny. I would love to see more of that. And I'd like to see more short skinny manly dudes. Man, that would be awesome. 8D
Anything that defies conventions is just wonderful. Non-conventional looking people in relationships, that's where the money is in my opinion. ^_^
And I will shut up now. 8D