The items I used for this was a small nail art brush, nail polish remover, two contrasting polishes and a cocktail stick. The cocktail stick was using instead of a dotting tool, so if you have one on them feel free to use it.
Now take the small nail art brush and dip it into the nail polish remover. I tipped out a small amount into the lid of the bottle as I felt this was easier. Then begin removing the polish in a semicircle shape near the bottle of the nail. I found this was easier with wet polish, as it came off easier. Remove the polish bit by bit to avoid a mis-shaped semicircle.
|Semicircles removed with nail polish remover|
Tip out a bit of the second color onto a work surface and dip the cocktail stick into the pool of polish. Next gently touch the edge of the semicircle you have created and go back for more polish every two or three dots, to keep the dots a similar size.
|Dots created by a cocktail stick|
I sealed this design in with a clear top coat to prolong it's life.
Here is the finished design: