Adding color to your flash adds vibrancy to your images. Bouncing off a white reflector softens or eliminates shadows.
The white reflector is a great fill light. Gold warms the photo, mimicking the sun. Black can be used to reduce or block light. Silver is the strongest and can add a lot of reflected light.
The idea here is to make some reflectors that are inexpensive and work well.
Foam-core (1/8" or 1/4" - thinner is better)
Self adhesive Velcro
Two sided Velcro
Gold, silver and black spray paint
Step 1: Wrap the Velcro on the Flash / Speedlight - Dry Fit Reflector
This is a really simple project. To save space, on one I leave one side white, paint the other side black. On the second one, I paint one side silver, the other gold.
One reason I love this style Velcro is that it does not need to be glued or stuck on. It's two sided - hook on one side, loop on the other. Wrap it with the "loop" (soft) side out. You want about 1" of overlap, with the overlap on the opposite side of the flash from the reflector.
First cut the foam-core. The final size is personal preference and depends on your flash / speedlight. If you have a big speedlight, you may have three or four inches of area to "grab" the Velcro. A smaller speedlight may only have a couple of inches. You want about 1/2" of reflector on either side of the flash head. You can also cut the foam-core with a wider top than bottom. Pay attention to the weight!
Apply a piece of adhesive backed Velcro to it. Stick it in place. Is it solid? Does it wobble? Too big or too small? This can take a couple of tries. If it's OK, than your first reflector side is done.
Cut another piece to the same size.
Step 2: Paint Your Colors, Add Velcro
Paint the other "reflectors" and apply the self-adhesive Velcro after the paint has dried at least 24 hours.
Step 3: Mounting Options
I have pretty big reflectors and double-secure them. First I attach the reflector to the Velcro, then I wrap another piece around the reflector. The second piece does not "connect" to the Velcro on the reflector because of the direction the hooks are facing, but it adds a lot of stability. You can optionally add another strip of Velcro on the reflector - a loop side - then use that as a second attachment point. This will also pull the reflector towards the flash and change the reflection angle. It's foam-core - it's cheap. Experiment!
Changing the height of the Velcro on the flash head also changes the light as the reflector length above the flash is modified. If you really want a larger reflector, you can always use two or three Velcro loops on the flash head and matching strips on the reflector. Just keep in mind that you may need to fit those reflectors in your camera bag!