Draw a Picture - I know, I know - you're not an artist, you're a writer! But... fact is, it doesn't have to look pretty. It just has to function as a blueprint, of sorts, to help you as things move around. I might be cheesy, but there are times when I even like to put little army men on it once I have it drawn out, and move them around as I write, changing their positions to match what is going on in the fight.

I make the pictures detailed. I put the alarm clocks, discarded socks, pictures on the walls, etc. That way, when the characters move over there, I know exactly what they will disturb during the altercation.

Create a Miniature - Sometimes all it takes to make a miniature is some cardboard that's cut out, or some small toys. This method seems a little more playful and a little less art, but it is actually surprising how much it helps to move people around and make a visual this way. The benefit over the drawing, of course, is that the miniature model would be 3-Dimensional, whereas the picture is flat. You can actually knock the table over in the miniature, which is amusing in itself.

Pipe Cleaners - Pipe Cleaners are excellent for creating a blueprint as large as you'd like for really cheap. You can also make it three dimensional by putting the corners of the walls, etc. You can create a see-through model in which to visualize, and it is a whole lot of fun. (And colorful! If you like colors...)