Make your hand signals BIG and long-lasting. It may take a moment for a driver to figure out what you are telling him. Avoid riding at dusk or later if possible. If you must absolutely light yourself up. Blinkies front and back, high-viz jersey or vest (I have the Nathan vest), I also put a headlamp on my helmet and although it really doesn't look"cool" I have dayglo-green wheel lights that outline my wheels both front and back when in motion. I make quite a spectacle of myself but have had drivers actually thank me because there was no doubt I was there. Know the traffic laws and obey them so you don't get hurt or look like another jerky spandex-wearing cyclist. Finally, recognize that even though you have the right to be on any road that isn't restricted there are just some roads you shouldn't ride on period.