RydeSafe.com offers great reflective stickers for your bicycle. I bought a chain wrap kit, a medium hexagon kit, 2 large modular kits and one small modular kit. That was enough to thoroughly cover my bicycle. There is room for more, and you could get by with less. The chain wrap kit was a waste of money as shifting gears will eventually wear them off. If you have a fixie, that would not be a problem. I wish I had more hexagon stickers. I liked the modular kit too, but because of their shapes, they tended to catch on things and begin to peel away at the edges more easily. The most visible and most secure place to put the stickers are on the rims of your wheels. The downside is if you get in a wreck, you will likely have to replace a wheel and loose the stickers. The helmet and anywhere else on your frame is good. Think about what parts cars will be most likely to see. Consider applying a few coats of reflective paint to help glue down your stickers. They do stick quite well, but they are not invincible. The biggest downside is that they are expensive. If you can fit it into your budget, they are very reflective - much more reflective than the reflective paint. All reflect white, but for the day time you can choose many different colors. Many people choose to be creative and decorate their bicycles. I personally chose black to match my bicycle. During the daytime, it blends in quite well and is not noticeable. In the headlights, the stickers are clearly visible.
The picture above was taken with the flash off, and some normal indoor lights behind me. In ordinary daylight, the stickers look black, but with just a little light behind me, you can see the reflective stickers. With that small amount of light, you cannot see the reflective paint at all. In the picture below, the flash was on (similar to being directly in the headlights). The reflective stickers seem to shine, but the reflective paint is visible. The reflective paint is helpful, but is far inferior to the reflective stickers.
Pros: Very reflective, weatherproof, sticks well but not immune to peeling, color options
Cons: Expensive, shapes likely to catch and peel
Summary: Great product for night time riding. Get it if you can afford it. Reflective spray paint is an inferior but more cost effective alternative. I've also seen reflective duct tape at Walmart. I think it was in the automotive department. I haven't tried it, but it should also be a cost effective substitute, but they only come in and reflect red, yellow, and white. Be careful to have red facing the rear and white facing the front so you don't confuse drivers.
