You don’t need me to tell you why you should use a ring light with your DSLR. But many rings available on the market are pricey or don’t perform as well as they should. You could always make your own though. Take this creation by Adafruit Industries: you can make it with a 60x NeoPixel Ring and use a 3d printed light ring adapter to hold the electronics and mount to any DSLR. This video explains how you can pull it off:
This light is great for macro photography and adds a cool effect to your photos. Best of all, it looks like a fun DIY project.