A good mentor is worth many thousands of practice sessions with non venomous. That's my suggestion if you want to get into keeping hots. It's not the only way but it's definitely the safest and wisest option out there.
Now, for colubrids with attitude, there be plenty of fun options. Some will calm down naturally, even keeping handling to a bare minimum, but there are some species that seem more inclined to resist the process. If you want to keep them aggressive, you need to let their bluffs actually work though. Let them think that putting on a show and throwing a hissy fit gets them what they want - you gone. Keep handling to a minimum and know when to end a session if you want the snake to maintain these behaviors.
Two of the more resistant to taming colubrids I've encountered in my neck of the woods are Coluber constrictor priapus and Masticophis flagellum flagellum. These are both site predators and pretty fast so you can get decent practice with the hooks but not really anything to prepare you for a hot of similar speed and agility. Coluber and Masticophis will stand their ground and throw some rapid fire strikes at you if cornered but they're going to bolt at the first opportunity. Compare this with Naja or Dendroaspis which are coming straight at you with greater speed, with greater agility, and their tag is sending you straight to the hospital.