What pranks should I pull on my dad and his GF?

So its late at night and I want to prank the whole house (and my friends here) we already re arranged the drawers. were going to put plain white printer paper on the door so when they open the door it will be just white and were putting a bunch of cups in the living room filled with a little bit of water and we put a sign that says honk if you like peace on the back of his girlfriends car what else