Hi chaps

I'm curious to know how involved it is for me to knock up my own custom Android ROM? I own a ZTE "Blade" handset (supplied on Orange UK) and I simply love it. It's been rooted since day one, and I loaded a custom ROM onto it to get rid of all the superfluous (and buggy) Orange junk, but I'd sure like to have a bash myself.

If anyone could steer me in the right direction, that'd be amazing!

Thank you