Where's the light?

I spent a part of Sunday learning a bit about the lighting equipment I purchased. I setup a test in the dining room to look at how to create different moods and effects by changing the lighting. I didn't have much time which in itself is a good test because when you're working with people, you don't want to spend 30 minutes setting up - people just won't have patience for that.

Here are two resulting shots, both have an sb900 on camera to trigger the off-camera sb600 through a shoot through umbrella. I tend to like the one on the left as it gives more of a warm feeling vs. the more direct lighting from the image on the right.
Next thing I need to do to prepare for the shoot at the end of the month is think about the types of shots I'd like to end up with at the end of the day. I want to keep low expectations but I also need to think optimistically that I'll get more than I was hoping for.