Here's a great diffusion filter that costs next to nothing. Get a piece of cellophane wrapper. Crunch it up (as crinkly as you desire) and pinch various-sized holes in it. Wrap it over the lens and secure with a rubber band. Move it around over the lens so one or more of the holes gives the desired look. For even more effects, try colored cellophane.
_ —Reader tip from Roy Blinston Queanbeyan, New South Wales Australia_