I agree with how Petrah does it. I've got a druid main atm, which means I can generally use all leather drops. I'm main spec Resto though so I generally wait to see what everyone rolls if I want a piece for offspec.
I know you put a macro up when you entered but its possible not everyone saw it. I'd suggest you add something to it that gets them to respond to it. A question or something. So you know that everyone in the group saw it, if you are worried about it.
Sorry you had a bad experience though. We all get crappy LFGs occasionally, least you aren't a dps thats sitting there for 30+ mins waiting on a group. Its easy for you to queue and go. Remember there are other players on the other side of those toons - alot of people tend to forget that - and they are playing their game just like you.
