I think of all the stuff around my house. The car is a bug one, but also my mitre saw, table saw, and any other powered saw. Also my ladder, mandolin (the kitchen one, not the instrument), and large knives. The things I need to be sober to use safely.

There's also "light machinery", which i can use when i'm less than sober but not super messed up on anything. My lawn mower is a push mower for example, so as long as i'm good to walk I can mow the lawn safely. Using a drill/driver is fine. Sanding, even the electric sander, is fine. Soldering is fine. I might have a drink or two and work on my server, either hardware of software, but I have learned to stop if I get too drunk. One of the most important parts of enjoying marijuana is learning how to make food while high.