We did this last year for the first time. Maybe I'll get back out and revisit this.
We used black foam core and built a 3 sided box to blow the bubbles in. This way it gave us a perfect black background.
If you shoot slow enough and get lucky with the timing you can get some pretty cool pop photos. Frozen bubbles pop a lot slower, kind of like a slow balloon rather than a regular soap bubble.
At 1/160 and plenty of tries you should be able to get something like this.
Bubble explosion by
Trevor Baldwin, on Flickr
Adjust your white balance into the reds for this.
Bubble fire by
Trevor Baldwin, on Flickr