I have inside my garage a ground anchor in floor, as close to a wall as possibly allows the chain/cabel to get through, with u-shape running 90 degrees to wall well under bikes so makes it difficult to bolt crop and another bolted/concreted into wall with a seperate chain/cable so they have to cut at least 2. using the best chain/cable and locks you can afford.
I then use as many crappy locks as I have to lock up everything just to make it more hassle for the bandito's.
To combat roof break ins I have at great pain cut in concrete mesh into the roof space so nowt can get in or out.
Doors the rear person door is steel faced, no window and has 2 5 bolt losks then inside 3 throw bolt type lock/hasp, top, middle and bottom then an old fashioned massive 6" by 3" lump of wood that drops into L shaped clamps that lock at the top to prevent the door being shoulder barged open.
The front up and over door which will be changed to a roller when funds allow I have over the standard 4 way lock, 2 clasp locks in the bottm corners, a garage defender in the middle to prevent it being lifted up. I then screwed a lump of wood the width of the door to prevent the top of the door being pulled forward/folded over.
There are security light and I reverse the wifes car tight to the door and then mine up tight against hers.
So hopefully my little beauties are safe – but you never can be too carefull