TBH most of it is a waste of time. The best thing to do is get a big play pen. Then you can throw them in there when you can't watch them and the rest of the time, you can see them.
Unfortunately mine broke the play pen before they were 18 mnths. So we have childproofing but most of the time all they do is slow them down. In our house, stairgates get climbed over or yanked right off the walls. Cupboard locks get snapped right off, the video lock got pulled off and the video filled with toys until it shorted out. For some reason it is so much easier for a baby to yank off a video lock than it is for an adult to remove it.
I have cabin locks on all the main doors, but they stack things up then climb up and open them anyway - dt2 drank from a bottle of perfume when he got in my room.
Def get window locks though, dt2 opened a closed window and jumped out of the first floor window. Now, the window is always locked shut when they are in there, the child lock is in case I forget.
Don't bet on childproof caps working neither, dt2 managed to open a sealed tin of paint and throw that over the patio.
Corner protectors get yanked off, a room partition thing was snapped, a seat belt security thing was ripped to shreds. Socket covers jsut make the sockets seem even more interesting, and then dt2 wondered wt else cud be poked into it. Locked garden storage boxes were solved by demolishing the entire thing instead.
The front door stays locked and the keys in my pocket, dt2 once let himself out of the locked door, opened the car, and got himself into ds1's car seat and sat there looking pleased as punch. I thank god that he didn't decide he wanted to drive the car!
Get rid of what you can, and don't let toddlers out of your sight!