Mix convenience and safety to force yourself to use the gear.
Think about how you will start to work on the vehicles. Chances are extremely high it will be exiting from the main house into your garage wearing 'regular' clothes. You'll be in the flow, and you'll be tempted to just start working. Engineer yourself a system so it's as easy as possible to use the safety gear.
Mount the safety gear next to the wall where you will actually use it.
Get a hook for your lab coats. Load the pockets with a pair of goggles and a pair of gloves. Practice donning and doffing the gear a few times. Now you'll be able to move faster than changing your clothes. That's the primary benefit to this approach. If you switch to work clothes first your much less likely to put on the safety gear. It's slower as well, and for a 10-20 minute job you can easily spend half that time changing clothes. Use the lab-coat approach to force yourself to use the safety gear.
Add a fire extinguisher right next to it.
Get an eye wash station - you will almost certainly use this. Even with safety glasses on (goggles provide a seal around your eyes and are rarely used), you'll be sweating, underneath a car with dripping fluids. They will run down your skin and into your eyes. You want to be able to immediately jump up and flush that out and get back to work. Go ahead and practice it, you'll feel much more confident afterwards.
Pre-emptively ventilate
Go ahead and swith on the fan with the doors open before you start working. Taking a deep breath of some chemical is a terrible way to go from vertical to horizontal.
Flex your backside to prevent from passing out
You'll be on your back under the vehicle, you stand up quickly to get a tool and feel light headed. The number one thing you can do that works every single time is vigorously flex your gluteus maximus muscles. This lower body clenching is what fighter pilots do to prevent blacking out. It's the same thing. It works.
Switch cut level on the gloves.
This is not for today, but for tomorrow when you need to type fast to make money. Got a nut to bust loose or something heavy to drag? Use the demolition gloves to protect your knuckles from cuts, abrasions and the internal stresses that come from tool pressure points. This is a non issue for many people, but if you have super soft and small programmer hands like yours truly it helps significantly.
Listen and trust what you hear.
If the tool sounds off all of the sudden, put it down. If the motor is whining, or something starts hissing, back away. If the wrench turns to easy, take a breath. These are all the signs that something is about to go wrong.