If you're the maid of honor, a wedding guest, or a member of the bride's crew, please don't wear white to the wedding unless the bride asks it.
Even if black tie is not your preferred attire, you should still follow the instructions on the invitation if they specify a certain level of formality.
One of the worst things that can happen is for friends to look at wedding photos and wonder, "Who is that person?" years later.
Avoid going against the preferences of the newlyweds as much as possible by giving a "unique" wedding present.
It's better to keep those embarrassing anecdotes PG-13 while you're among family, as things may rapidly become awkward otherwise!
They should be applauded and greeted, but you shouldn't take up too much of their time as they work the room.
This rule should go without saying, but you should not attend if you were not invited. And if you receive an invitation without a plus-one, do not bring one.
If you are single and looking for love, it is completely okay to flirt at the singles table.
Showing up late to the reception and then following the bride in will make you look careless. In the same vein, you shouldn't arrive late to the reception.