Basically I've followed the equilateral triangle setup as a start.
The distance between the speakers and the listening position form an equilateral triangle.
Placing absorptive panels at the left and right points of first reflection and on the wall behind the speakers.
Getting the tweeter as close to ear level as possible and using toe-in to focus the stereo image on the listening position.
I'm not sure if your interested but there are some recordings that are fantastic for setting up imaging with speakers.
Jennifer Warnes Ballad of the Runaway Horse is perfect for imaging and for bass.
The Acoustics Sounds SACD of Elvis is Back specifically the track Fever, is scary good for imaging and set up in general.
You can also buy the Stereophile Test CD which has a lot of tracks to test and illuminate system setup.