Since we can't see a pic I'm guessing its like a piping on the Ed of a jacket? Sew on bias tape!
Adelheid (KHR!)- 85% done
Fem!Austrian War Succesion France (Hetalia/Nyotalia)- 10% done
Fem!Izaya (Drrr!)- 90% done
Magent!Teto (Vocaloid)- 95% done