It's interesting to think about the traditional character alignment axis of Lawful-Neutral-Chaotic and how it would actually work in practice. Especially among groups of villains.

Try giving your villains, if not strictly defined alignments, at least distinct personalities and approaches to what they want. Having your bad guys bicker amongst themselves a little bit gives them an air of realism. You probably shouldn't get too carried away with it though, lest they make your heroes entirely redundant.

Transcript

Tàrkin: Is ze Senate settled in?
Darth Vader: They're meeting in a closed session, as we speak.
General Tagge: Secretive bastards.
Tàrkin: To which zey 'ave, 'ow you say, ze constitutional raht.
General Tagge: Says who? They do! What are they hiding?
Darth Vader: Of course, the law must be upheld.
General Tagge: And as I've always said, they should be able to make their decisions without interference.
Darth Vader: Therefore, we must eliminate the Senate.
Tàrkin: Ha ha ha! Ah, Monsieur Vader, you are such ze zhokeur.
General Tagge: Ha ha ha!
{beat, Darth Vader glares at Tagge}
General Tagge: Er. It's funny because... I hate the Senate so much?