I've just started a new playthrough as a witch character and I thought it'd be fun to have her be an assassin. While casting spells in combat is fun and all, I like more sneaky types of killing (e.g. slipping poison into people's pockets).
I came up with an idea for casting spells at a distance via hex bags placed in the victim's home. Once they enter, they take damage, and as long as no one saw you break in, you don't get caught. A similar way to do this would be via some sort of voodoo doll; you attack the doll out of sight of the victim or witnesses. They take damage, you don't get caught or get your hands dirty.
I don't know how difficult something like this would be to make, but it sure would be fun to use if someone wants to do it! (Or tell me how to do it! I'll make it myself if someone wants to give me some pointers.)