Florida is statistically the deadliest state for cyclists, with nearly double the fatalities per capita of other states. You need all the help you can get.

I'd strongly advise two lights front and back. Two points of light help drivers quickly estimate your distance, orientation, direction and speed. Separation between lights helps. Easiest way to do that on a bike is mount at least one light on the bike and one on the helmet, front and rear.

After seeing another cyclist use that technique I could easily see how visible he was compared with other cyclists, especially in traffic. Even when his bike was blocked by vehicles I could still see his helmet lights above the rooflines of ordinary cars. What really grabs attention is when the cyclist turns his/her head -- it really pops out amid the clutter of most urban lights, which are usually either static or moving in one direction.

That's when I began using helmet lights myself. On the few rides when I didn't mount lights on my helmet I'd mount two headlights and two taillights on the bike. To get some separation I'll mount a headlight on the handlebar and another on the head tube or fork. On the back I'll mount one on the seat post and a second on the rear rack or seat bag. It's not as effective as the helmet lights, but better than single lights.