What (if anything) did you do/are thinking about doing at your wedding that goes against proper etiquette?
I really don't mean to start a bash on each other thread, it was just something I was thinking about.

On the inner envelopes for my invites, I did not address them formally. I did address the outsides formally - Mr. & Mrs. Bob Jones, but on the inside I would just write Bob and Sue.
We provided beer and wine for our guests, but did not pay for the other liquor. We only served beer and wine at the upstairs bar, but there was a bar downstairs (our reception was only upstairs) and that bar was serving everything. So in a sense, we were only providing our guests with what we paid for, but if they wanted to get a drink from downstairs, there really wasn't anything we could do about it. We couldn't make the bar close to its regular customers.