Tips on sneaking off/sneaking out without parents finding out?

Plan a route. Find the squeaky floorboards and/or door hinges. Look out the window at night and find the areas with deepest shadows. Plot the route you'll take to get out of the house. Once you're out, get a good distance away - anywhere from three houses to a block, depending on how quiet your street is - and get your pickup. Make sure that people don't talk about you sneaking out or your being at a party, especially not online. No guarantees that that'll work, though.