I have a mirror, two lights, a atv kill switch, speedo and a horn.
I use Normans light to see with and use the cheap bell light in the flashing mode. Some will also use a double brake lever so they do not have three levers (clutch,& two brake leavers). I had a home made dual brake lever, but my front brake and rear coaster work so well I decided to get ride of the second rear brake.