u can use velcro and not have it show. u just have to make part of the cast overlap onto the other side. but this all really depends on what material u are making the cast out of...
Adelheid (KHR!)- 85% done
Fem!Austrian War Succesion France (Hetalia/Nyotalia)- 10% done
Fem!Izaya (Drrr!)- 90% done
Magent!Teto (Vocaloid)- 95% done