20 Garage Safety Tips

In no particular order...

1. Unless you are actively working in your garage, keep the garage door closed (an open door can be an invitation to thieves or worse).
2. Unless you are actively working in your garage, keep the door between your house and garage locked.  Many people don't lock a door on the other side of a locked door but it is an added deterrent should someone gain access to your garage (at least they will have a difficult time accessing your house if this door is locked).
3. Don't park your car in your driveway and leave the garage door opener in it.  It is a simple thing for a thief to break your car window, get the opener, then open your garage door (and then access your house because reason #2 above).
4. Don't leave your garage door opener in your vehicle when you leave your vehicle with the valet (this will give them your car, your address on the registration, and access to your home through the garage).
5. When you back out of your garage and hit the garage door opener to close the door, make sure it closes completely (the sensor on the door can sometimes sense something in its path, open, and the garage door will stay open until you come home!).
6. Keep your garage neat and organized.  Having junk all over the floor of your garage is a good way to cause falls, cuts, etc.
7. Lock you car doors even when the vehicle is in the garage.  Again, going back to #2, it is yet another precaution to keep thieves from easily accessing your stuff should they breach one locked door.
8. Store chemicals and fire hazards (like chemical-soaked rags) appropriately.  Info on how to do this here.
9. Don't store certain items in the garage ever (like extra cans of fuel which could cause an explosion and wipe out your house as well as the garage).  Other items not to store in the garage can be found here.
10. Keep a charged fire extinguisher in the garage in case of emergency.
11. Make sure your garage door opener is of the newer variety which has a reversing mechanism when it senses something in its path.  The old door openers won't sense that there is a child, pet, or other item in its path and this can prove deadly.
12. Keep your garage "kid proof" (even if you don't have kids).  Safely store ladders so they can't fall on someone, never leave electric tools (like saws, trimmers, etc)  plugged in when not in use, use locking cabinets for dangerous items, etc.
13. Back your vehicle into the driveway/garage.  This is a safer way to park a vehicle (you can easily see what is in front of your vehicle and prevents back-over accidents when exiting your parking area) and a faster way to exit your parking area in an emergency.
14. Beware of the danger of carbon monoxide poisoning.  This can happen when you run your vehicle's engine in the garage, when you move your barbecue into the garage during rainy weather to use it, etc.
15. Soak up any spills/vehicle oil leaks/fuel leaks from the floor of the garage.  Besides being a slip and fall hazard, this can also be a fire hazard if not cleaned up immediately.
16. Make sure the lighting in your garage is adequate.  Many garages have a single light which doesn't help much if you are working on a project over in the corner of your garage.  All areas of your garage should be lit up, especially areas here you will be working with tools, table saws, etc.
17. If you have a video/audio/motion detector security system in your house, don't forget to add these systems to your garage.
18. Don't allow kids or pet to hang out in the garage unattended.  This can be dangerous for a number of reasons including high temps in an un-air conditioned garage, the possibility of kids getting stuck in a refrigerator or freezer which is kept in the garage, accessibility to poisons, etc.
19. Consider installing a smoke detector and carbon monoxide detector in your garage.  This is an added level of safety (but note that some of these appliances can be very sensitive to dust and very high/very low temperatures).
20. If you store kid's sports equipment in the garage, make sure the kids can easily access the items (ie: kid's shouldn't have to climb up to reach their roller blades, life their bikes off of high bike holders, etc).