9. Take care with the seating plan
You're never going to want to hear the words "table plan" or "seating plan" again after your wedding. Forget finding the dress or writing your vows, this is the most stressful part of the whole thing. No matter what you do, the numbers just won't quite work — there's always a big group you have to split, a child who throws the numbers off, or a feud you have to deal with (but not draw attention to). You'll consider all kinds of silly ideas (at one point, my husband and I pulled names out of a hat and placed them randomly on the plan), but eventually you'll have to just make some compromises, try to group like-minded people together, and hope people will cope for a couple of hours.
10. Consider providing some creature comforts
Umbrellas at the exit, flip-flops by the dance floor, a few little extras in the ladies' toilets (blister plasters, tampons, mints, nurofen); if funds allow, pay attention to the little details that'll help your guests to have a great day even if things go awry.