To do really cool bokeh's it's best to use a lense with a really wide aperture, as this means the background will be out of focus :)
The bokeh will take the shape of the aperture baldes of the lens that is being used, so it might appear as pentagons, hexagons etc.
In this blog i'll tell you how to make your own personal bokeh shapes :)
1. First of all you need a lens with an aperture of f/1.8, make a note of the diameter of the lens (this should be written on the lens) you'll also need some lights to make the bokeh, e.g. christmas lights.
|this is the filter i made|
3. then cut this shape out with either a craft knife or small scissors :)
4. then simply push the card into the lense and you're ready to start shooting, if it doesn't fit perfectly you can always use some masking tape to hold it in place.