The Canadian Centre from Occupational Health and Safety conducted a review of safety best practices around falling injuries. As falling is the second most common manner of injury in the garage, it's worth giving their report on the subject a careful read.
To minimize trip hazards in the workplace, the CCOHS report recommends the following:
· keeping walking areas clear from clutter or obstructions
· keeping flooring in good condition
· always using installed light sources that provide sufficient light for your tasks
· using a flashlight if you enter a dark room where there is no light
· ensuring that things you are carrying or pushing do not prevent you from seeing any obstructions, spills, etc.