These ear cuffs are designed to be printed with flexible TPU filament for comfort. It makes them lightweight, but can also make it easy to knock them off if you tend to fidget with or touch your ears a lot.
You should print the cuff part with a clear or natural color and the spider in black (or your preferred spider color).
For the small one, I designed it with a rectangle stick out on the cuff and corresponding cutout on the spider. It should only fit two ways. Once they are both printed, orient it the way you want and glue it together with super glue.
For the large one, I decided to design this one with a sphere stick out on the cuff and corresponding cutout on the spider. This gives you more freedom on how you orient the spider. I went with making it look like it is crawling up my ear. You can test the placement as it fits in nicely and then glue them together when you decide on how you want it.
The print file has both pieces in it, so I recommend splitting them up and printing them with different colors.