My aftermarket turn signals were pretty dim, so I decided to make them brighter.....way brighter! So I took 14 super-bright orange LED's, hooked them up in series, put in a current limiting resistor array, and voila.....damn bright turn signals. Now they match my LED tail lights. At least I don't have to worry as much about getting rear-ended while waiting to turn left.
All this for about 2hrs of work (materials were free).