Now, a few words about light. Obviously, light is a perfect addition to something as reflective as balloons. This is their very first property - to reflect light. This is the reason for the balloon popularity in the first place! So any lighting equipment will work very well with any type of balloon decorations. But there are several points worth making.
Obviously, we are talking about the low light parties, all this tricks would give you very little if the sun is shining through the windows.
Ask DJ to bring all the lighting equipment he has, especially if it is in the package and it does not cost you any extra, or not too much. It is a well spent money.
Obviously, you can put some light on the balloon decoration, the decoration will get a lot of attention.
Next, it is very beneficial to backlight balloon decorations (or any decoration for that matter). By that I mean that the more light you put on the wall behind the decoration, the better it looks. You can rent a stage light (which means that you or someone has to go to a rental place, take it and return it after the party) or even get working lights at the local Home Depot and use them. The only thing to keep in mind is little children. Stage lights or working lights are relatively hot and must not be touched. If you can not absolutely guarantee that kids will not get there - do not use it!
Here are couple of examples of the backlighting - "Josh" and "Jazz" pictures below.
And, the at last, my absolutely favorite - balloon blinking light. This is a LED light so small and light, that we can put it inside a balloon and it still is going to fly! It can shine steadily, blink slow or fast. It turned out that so far the best use of it - put it on fast blinking and glue it on the balloon sculpture or on the centerpiece - in quantities! What makes these light so good is the fact that they blink independently, not like Christmas lights. The result is just amazing! It is hard to show how the blinkers work on the picture, but easy on a video. Here are couple of the video from our Bar Mitzvah decorations:
The only thing is that these lights are relatively expensive: there is a price, cost of shipment, each light is individually packed in a separate little bag, so someone has to get them all out, turn them all on to test, and only then it is ready to be used. But it looks gorgeous, blinks for about 3 days, so it is a grate tool. However - it is absolutely useless if used in a room with a bright light.