Practice.

Beyond that, it's mostly personal preference.

If I were setting it up for me, I would probably go with a DAO/bobbed hammer. Depending on how the trigger was I would consider having a good gunsmith smooth the action while retaining the factory springs. Probably try to find some decent grips (my biggest complaint about the SP101s is the lack of grips that would suit me). I like plain black sights, so I might just paint the rear sight black. Dehorning the exterior might be worth doing.

I would not consider any of that "required," though.

Except for practicing.