A visible helmet, with front lights and reflective stickers.
Step 1: Helmets Are Good, They Add Protection But Little Preventative Measures. .
Add visibility to a helmet using a front facing light, it helps you see and be seen. there are many designed to fit a helmet
Step 2: Reflective Tape Is Good in Daylight and Night Time and Because Your Head Moves When You Ride It Catches Drivers Attention
make sure you add reflective tape that will not deteriorate the case of your helmet. some adhesives will damage your helmet. opt for water base and plastic safe. AVOID sticking things to the foam of your helmet, only the pretty outer case.
Step 3: LED Side Lights.
the light strips are pc modder strips, pre-adhesive, purchased from pc mod supplies on ebay.
I've used 4x3v CR2033 "button cell" batteries. these are mounted in a small cardboard tube and water proofed with a cut up wheel inner tube. they are then strapped to the outside top of the helmet with cable ties. I haven't installed a switch so I'm just twiddling together the wire to turn it on and taking it apart to turn it off.
I'll go out and buy a switch tomorrow.