One option to secure an up-and-over garage door is a garage defender lock. It is a heavy-duty metal arm, padlocked to a base plate that is bolted into the concrete outside the garage door. This prevents the door from being opened.

Alternatively you can fix bolts to the runners of an up-and-over garage door that can be locked from the inside.

This is a particularly good idea if you tend to enter your garage from inside your home, and not from the outside.

Don't help burglars by leaving tools lying around. They will simply use them to get into your house.

In particular, secure ladders by chaining and padlocking them to a solid fixture on the garage wall.