When it's time for the cutting to begin, sit up straight. Don't fidget, and keep your legs together on the foot rest -- crossing them will give you an uneven cut. Feel free to chat with your stylist, of course, but also keep an eye on what's going on. If you think the stylist is altering the cut you agreed on, say something sooner rather than later. Do it in a polite way, obviously, and try not to micromanage, but don't be afraid to speak up. If things haven't gone too far, the stylist should be able to fix what's wrong -- or reassure you that everything is, indeed, going as planned.