Here above is a picture taken without a ring flash it make a very hard dark shadow and light is coming from above te camera. Also it have part where the flash is bit too bright.
Here is the same shot with same setting but with a ring flash. You can see the picture is a bit darker but if the setting is changes it could have the same light level as the other picture. But you can see several different like you have a less dense shadow with less or no hard edged shadows. The plastic also is different you see more details with in the plastic.
I made this ringflash template here above for my Canon 1000D you can download it by clicking the image and then use rightclick to save the image. The ringflash uses your standard flash light from normal camera. This ringflash should fit also other Canon camera’s with the same dimensions of the canon 1000D. The template uses a slot system to put it together so you can also disassamble it so it is easier to place it in your bag, however you can past it together to have a solid version instead. I recommend to use a hard white cardboard to put this together or use pvc sheets you can buy at different art supply store. However PVC sheets are hard to glue but is more for the version that you can easier assemble and disassemble. Also white seem to be working the best for reflecting te light correct I used chrome vinyl on one of my prototypes to relect the lighting but te there was so little light diffused to be making a ring flash work, while while white works much better.
The template need to be printed on an A3 or you need to use photoshop to slice it in 2 pieces so you van print it on 2 A4 sheets and put them together and place it over on to a hard cardboard to make this ring flash.
Here is an updated version plus instructions how to put it together.