Speaker Positioning

A tip if you have a symmetric room and are trying to get the speakers in the same spot with same toe-in.  Cut 3 boards or dowels.  On that is the distance from the front wall to the rear corner of the speaker.  One that is the distance from the side wall to the rear spike and one that is the distance from the side wall to the front spike.  You can then use these three to set the other speaker in the exact position relative to the front and side wall and the toe-in will be the exact same.  Again, this is only relevant if you have a symmetric room.

Is speaker placement not also dependent on the type of speaker? I've had dynamic, electrostats, and currently horns and each required significantly different positions and room treatments to get the "best" sound. 

...I’m with Millercarbon all the way. Just sayin’

There is no perfect way. Put in a position where they sing to you. At that point you can add room treatments. If you feel you need a lot of room treatment you might have the wrong speakers or preamp or Amp. 

Get a book like Jim Smith "Get Better Sound". Read it and start there. There's no experience like your own experience.