Sponging is a technique used on walls to make sun-dapple effect, add texture and depth to a wall. This might involve adding two or more coats of paint to create this great effect.
The first thing you do is choose the color that best suits your style and class. For this you need to decide whether you will go with a subtle effect or a dramatic one.
If you decide to go with a dramatic effect, choose deeper and bolder colors. Note that these colors will attract more attention and you will probably find the wall dominating the room more than anything else.
For subtlety, you need colors that are not too different. Either way, your house or office is bound to look great with this kind of technique. A plus to this technique is that you can be creative and use between colors of your choice and still have the same effect.