Here are some basic safety tips when working on your car in the garage or automotive shop.
1. Support the vehicle properly. Don't go cheap and use some homemade jack to raise your car up off the ground, and don't use the bottle jack that comes with your car to lift it up, and then crawl under it. First use a good floor jack that can support at least 1 ½ tons. Once your car is in the air, use some good jack stands to keep it there. Never crawl under a raised automobile weighing several tons without the proper support.
2. Wear proper safety gear. This one seems obvious, but most mechanics just grab some air tools and go to work. Safety glasses are cheap and will save your eyes from falling debris. It only takes a little metal shaving to stick in your eye, and cause a lot of pain and damage. Mechanic's gloves are also available everywhere. They are thin enough to allow a mechanic to feel bolts and tools, and they still provide protection. How many bloody knuckles have you gotten from smashing your hand on the engine block?
3. Use the right tools. It is awefully tempting to just improvise with what you have on hand in your garage. Don't do it! Beg, borrow or purchase the right tools for your auto project. A good example is not using a good torque wrench. You can easily damage an expensive cylinder head on your engine if they are not torqued properly. Also, use a good transmission jack. Transmissions are made of soft aluminum and can be easily damaged.
4. Buy a good manual. This one will save you a lot of headaches, frustration and money. The old saying "when all else fails, read the instructions" definitely applies to the automotive shop and garage mechanic. Chiltons produces great manuals, and will more than pay for itself.
5. Common sense is not that common. Use your brain too. It is all too common to see people working a gas tank on their car with a cigarette hanging in their mouth, or working on a running engine with their neck tie hanging down over the fan blade.