Personally, playing Evil characters is easy, heck both my PCs are Evil in the current Conan campaign. I'm running a Lawful Evil assassin who follows a code of honor, is respectful, kind and completely ruthless and amoral. He's killed NPCs and tortured those who antagonize and mock him, but he shows complete respect for everyone else. His code is "Life is valuable and it's going to take a lap full of silver to justify me killing that guy over there." He's never stolen from anyone (ever!), he keeps his contracts, and he goes out of his way to uphold his code regardless of how things work against him. Heck, if he's forced to initiate combat he'll go subdual until someone actually hurts him.
OTOH my other PC is the stereotypical Conan mad sorceress. Magic focusing on elements/forces (Raven's rules) and feats and skills focused (obsessively) on building up science and technology. She's Neutral Evil and self centered, but the trick is you don't play that as stupid. She doesn't go out and burn villages for fun, she doesn't sacrifice random people, she makes plans, works on them and doesn't really notice if people happen to get ground in the gears.
The trick to doing Evil right is that all Evil isn't puppy eating. Some people are simply Evil by sociopathic mindset (both of my current PCs) where people are things. You don't have to go our raping every child you see to be Evil, you just have to not care about anyone who doesn't prove themselves valuable enough to you to make your effort worth assisting them. Basically, if they benefit you, you help them, if not, oh well. Heck, I've let major NPCs die because they weren't worth the effort to stabilize and I've spent Fate Points to make major NPCs "Left for Dead" because it benefited me in the long run.
Making you Evil PCs "Chaotic Stupid" is a sign of players who thing that empty orc mooks represent what an alignment is supposed to be. Orcs are an excuse to let PCs run rampant and butcher things without any morals, not a standard to define an alignment.