1. Don't let a helmet scare you. Yes, you should wear a helmet. Yes, you'd be stupid to not wear a helmet because despite what your parents told you, you're not as hard-headed as you think you are. But if needing a helmet is gonna keep you off a bike, well ... just try to be smart about it. Cause you should wear a helmet. But I don't (always).
2. Ride paranoid. Keep both eyes and ears on the road and on the drivers. Ride like at any moment any driver is going to do something stupid and illegal that will kill you, because that's the only way you'll see it coming. Especially if you're not going to wear a helmet.
3. Look out for pebbles. Cause they're littler than your little toe but they can fuck your shit up. You hit one and your tire scoots to the side and your heart is in your throat and that just doesn't get fun. So watch out.
4. Inflate your tires every day. If you have a road bike. If you've got a mountain bike, you can get away with less. But make a habit of it and keep a small pump on your bike because that 60 seconds it takes to check the tires is easier than changing them.
6. Keep a flat kit. That same pump applies here. Also, a wrench, tire levers and a spare tube. Trust me, it's an easy set to dump in and out of your bag and you don't want to be caught without it. On your own, you're screwed and with a group, you kind of feel like a mooch-y dirtbag.
7. Learn to change a flat. Guilty, sarge. I've got the kit and I've been shown how to do it and I've watched several people do it, but, uh, I've never changed my own flat. I'm like 89% certain I could do it on my own, but that's never been put to the test. But learn to change a flat.
8. Ride everywhere. Because really, you don't need a car to get where you're going. Cycling isn't just about exercise, it's about transportation and getting places with a little wind in your hair (wait, no, put that helmet on). The more time you spend on your bike, the more time you'll want to spend on your bike.
9. Get a set of lights. Front and rear. If you're going to skip a helmet, you need lights. Seriously. I've seen dumbshits ride at night with no lights, no helmet and headphones in. Would you drive without headlights? No, because it's a step beyond stupid. So get some goddamn lights.
10. Love your bike. Otherwise, what's the point?