Which dumpsters do you divers check to find things?

Im not a Dumpster Diver, but seeing people finding crazy things its impressive and I want to find things too

For now, I have only found an acoustic guitar, some chairs, 20 books, a box of clothes and other things

I want to know where to start to find even better things

Any suggestion would be really apreciatted!

And apart question, im more interested in finding musical instruments, which dumpster should I check?

Thanks in advance!