In many videos showing rows of baloons being popped I noticed they move around a bit. Here is what works for me: Run a strip of masking tape along the surface sticky side up. Run smaller cross-strips face down to hold it down, place your baloons about 1 inch apart and pop away. It provided a stable base with the results being better than expected. 
usually the blast from a popped balloon will tend to blow the others closest to it out of the way.