I've used these for years now, & tested many others. Jogalite especially worn on your ankles gives trailing motorists a light show that's hard to beat. I strongly recommend the silver ones, they seem to have more brilliance. Wear one on each ankle to maximize the up/down effectiveness. They make great gifts to people you love who are out at night doing anything. Put 2 together and put on your dogs neck. 

I ride with oodles of reflective bits on my main commuter, yet still have drivers oblivious to me. In order to rectify my wool jerseys that do not have reflective trim, I decided to give this highly rated, US made symbol a go. The reflector comes with a quick release buckle and strap that wraps around your middle. Can be strapped elsewhere, but that's where I use it. I'm comfortable looking like a bike nerd if it let's me see my children get older.

Great for running because this belt is highly reflective and really lightweight. The size adjustment stays in place. Once snugged, the belt stays in place and does not bounce around. I use a red belt for daytime visibility and a yellow belt for nighttime visibility both running and bicycling.