When you lock the main gate, please use the outermost hole. Otherwise sometimes other people can't turn the lock to the other side of the gate. If you have trouble with the lock please tell us so we can look at it. They do wear out, and also have to be oiled with the right stuff.
Always lock the gates unless you are right there watching it. This is one of the ways thieves get in. It's easy for them to get out as they can find junk on-site to pile up to get over the fence.
If someone you don't know tries to follow you in, ask to see their key. Don't be embarrassed to challenge them. Remember that we are sometimes targeted by professional thieves and they might not look as you expect.
The lock lasts longer if you hang it on the hook while you open the gate instead of dropping it on the chain.