Periodically cleaning up spaces on my MacBook Pro

Question

My MacBook Pro(Snow Leopard) runs slowly everyday, I want to know all the possibilities of cleaning up the unnecessy files and folders generated by the machine backup or whatever. I would like it to be when it's first purchased. What could I do?

Edit: Offcourse I understand that I installed a lot of softwares and stuffs. But is there any general guidance on what can be done to make my Mac run faster?

Answer 1

I sometimes use CleanMyMac, but mostly to get rid of leftover / temp files.

How much free RAM do you usually have? If you are short on memory, adding some could help.

Answer 2

I'd run applejack. You probably need more RAM if you have a lot of programs running.

Exact machine type would indicate RAM type used (like at kingston.com) and upgrade options available.