It is a good idea to wear safety goggles or safety glasses when you are doing windshield repairs and headlight restorations.
Do not wear loose clothing or bulky gloves when performing windshield repairs and headlight restorations. Long sleeves will give you a measure of protection from some materials, but can get tangled with items under the hood so there is a tradeoff, keep the sleeves buttoned.
Neckties and sandals are a no-no.
If you have long hair, I would recommend putting it under a hat, or wear a hair net to keep it away from moving parts.
Minimize distractions while working on vehicles. This includes small children, pets, friends, spouses, in-laws or others who may distract you from your work. This will go a long ways towards reducing the risk of injury and making a mistake.
If you’re working outdoors and using power tools, make sure the extension cord you’re using is rated for outdoor use, that the extension cord and tools are properly grounded, and that the cord has the proper amp rating for the tools you’re using.