One of the most important tips to safe cycling is to be as visible as possible to cars and pedestrians. In addition to head light and rear light I also attach a rear light to the back of the helmet for added visibility. This is a simple hack to add a rear light without zip ties or duck tape for a clean look. Note, this may not work on all helmets particularly ones with adjustment dials.
Things you'll need:
Rear bicycle light
Step 1: Step 1: Measure
Measure the width of clip on back side of light and the gap clearance to determine the amount of plastic you'll need to remove from adjustment band on helmet.