I see many people posting here with questions about lights and using them to stay safe out on the road. But I think that most of us depend too much on just adding more lights and more powerful lights in the hope that it will make us more visible. More bright blinky stuff on your bike only confuses and distracts drivers instead of helping.
Here's what I did and why:
I started thinking about this subject a few years ago when I had a considerable string of close calls on my commutes. Drivers seemed to be getting too close despite the zillions of blinking flashing lights that I had mounted.
Then I watched a show about search and rescue at sea. It told how survival suits were often tailored with reflective accents that help searchers identify a floating shape as a human. I started thinking about that as it applied to cycling. Specifically how it applied to cycle commuting where traffic is dense and maybe folks aren't paying attention to what's on the road.
I decided to use the mechanics of how human perception works.
First off... get rid of all those blinky things. The human eye has difficulty getting a distance fix on a blinking light. So I put a Planet Bike Superflash on steady mode on the road side chainstay of each of my commuters. That way drivers can easily get a fix on how far away they are from me.
Second... put a single very bright blinker on back to get their attention. The best blinky that I've found is made by Adventurelights and is available from many retailers under many different names. I bought one from RoadID for $18.00 but they are available from Amazon.com for under $12.00 right now. It uses two CR2032 watch batteries and is insanely bright. It is also small enough to clip on nearly anywhere and is waterproof to 300 feet.
Third... use reflective gear to help the human brain instantly identify you as a human. Note the word INSTANTLY. You do not want drivers to have to look at you to see a human shape. Lights are good... but they're just lights. You want drivers to see a human right away... you want their brain to instinctively see a human, not a conglomeration of strange lights. So I wear a reflective vest that highlights the torso. Just look at the kind that road workers and pavers wear... I wear a lightweight version of that. You want one that has reflective strips that go over your torso so that drivers see more than just a reflective stripe.
Lastly... and most importantly... add reflective gear that instantly identifies you as a human on a bicycle. Reflective ankle bands. I feel that these ought to be required equipment for any cyclist riding at night. Drivers see the smooth up and down motion of those ankle bands immediately know that it's a bicycle.
All of these things work together to attract a driver's attention, let the brain quickly and accurately identify you as a human on a bicycle, and to get a range bearing on how far they are from you. And reflective gear does not depend on batteries. I also strongly advise cyclists to buy high quality reflective gear. Some of the stuff on the market is little more than shiny silver paint... look for SOLAS (Safety Of Life At Sea) certified gear when possible.
Since implementing my strategy a few years ago, I have saved a fortune on expensive lights and my near misses have dropped to almost zero. The only close calls I have nowadays are from drivers who want to buzz me because they're jerks.
That's what I did to be seen on the road... now seeing the road is another thread topic!