1. Bring a spare pair of pants. (It's their day; they'll pee if they want to)
  2. Don't think you have to offer a full meal for every kid and parent attending. They're all just going to pick.
  3. Put "no presents necessary" on the invitation. Your kid had too much stuff already.
  4. Don't bother to provide enough cake for the parents. 98% will be too embarrassed to eat kids' birthday cake. But cut extra big pieces for the 2% comfortable enough with themselves to dig in.
  5. It's all for the children! (Yeah, right.)