No doubt you were overly socialized as a child. Probably by heavily guilt-tripping parents. Thus, your inner Jewish-mom voice chides you whenever you go to rape and pillage and kill innocent settlers ("Can't you find a NICE girl? That cottage was lovely! You need more friends..."), that sort of thing.
First, you need to play with a heavy, pulsing, driving insane beat music blasting loudly in the background. Anything by Gwar, Sepultura, Manowar or Julie Andrews should do.
Second, you need to get your head into some good, logically founded evilization. So it doesn't trouble you to raze that city and bump the AC up, with silly thoughts like "but I could -use- that city". If that city was
really useful, they would have defended it better!
Check things like Gordon Gekko's "Greed, greed is GOOD" speech in Wall Street, read "Justine" by de Sade, any good "survival of the fittest" type propaganda, or just watch broadcasts of most government debates/bill passing sessions.
Lastly, for inspiration, play the Balseraph's, specifically Perpentach. You're not REALLY evil, you're just whimsical! You're not bringing on Armaggedon, you're shaking things up a bit to see what happens. Change is fun! When your traits change, find a way to put them to use, or inspire a style change.
Got raider? Hey, spread Carnival to a few neighbouring cities! Got financial, hey, call it all off, sorry sorry, terrible mistake really, lets be friends and trade. Got aggressive? Build swarms of freaks (expensive but fun) and go rampaging. Got spiritual? Change religions and civics, JUST BECAUSE YOU CAN!! Build OO Asylums and launch Lunatics into the world, cause you can never be *too* crazy!
Hell, you can even be good every now and then and plant some forests or something, suck up some of Hyborem's CO2 emissions.
So there you have it, the Good Ol' Life-Lovin' Yeoman's Guide to Everlasting Evil!
Bust out of that narrow rut you're in, try it today!
