Man, I'm about to have the same problem - I know it. Last place was carpeted, high ceilings, and quite symmetrical. The place I just moved into over the weekend is hardwood floors, and ceilings that are about 4-5 feet lower. I haven't even had a chance to setup anything yet though because my studio desk bit the dust.. waitin for the new one to be built.
On the left of the setup I am going to have closet doors, on the right, a window. Hopefully these won't be too bad as they are out of the direct way of the speaker.. but I suspect I may get some funny reflections. Other weird part is that the left rear corner is where the doorway is, coming in at an angle. The other corner is 90 degrees...
Fun, Fun.

I think I'm going to try that Auralex acoustic design form that someone else posted. Gotta set everything up and see what the problems are first tho.