how do you make your own emulator?

it's a little bit more complexed than that....for one, you need to know how to program and secondly "an emulator" don't really specify what you would be wanting to do, but assuming you are talking in the DS Emulation thread I would assume you are wanting to make an NDS one

and if that's the case, then I would recommend not doing that unless you have done some form of coding before because emulating an NDS or PSP etc (new consoles) would be a hell of a lot harder than emulating older generation consoles

If you don't know how to program, you'll need to learn how. C and C++ are good choices for a language. If you know how to program, start off with emulating a simpler platform like Chip8 before you dive into the NDS. You can find a wealth of information in the threads stickied in the Programming forum.

a bit of a general question .. a general answer could be with programming and a lot of time does that help?

if not then you can always read a doc I wrote years back that explain the basics in a bit more detail at http://www.pj64.net/emubook/

lol, I thought it might be great to make an emulator just to play Sonic Rush

But I have no programming skills nor do I want to have any

Exceed well