I call upon my deity to "act out those curses". It just so happens to not be the Christian God or Satan or spirits. My juju tends to focus on powders, herbs and ocean water. There is also a saying in hoodoo - if you don't do the [root/conjure]work, nothing will happen. So I take that to mean that simply by the act of doing spells, it will enable them to happen.
@Hero- An un-curse curse is simply a curse break or uncrossing. It's fairly simple to make, so I tend to charge $5 USD for those (not including s/h). As for Rupees, it would likely come to the amount of 50 rupees.
Wouldn't there be some worship involved, then, if there is a deity involved? Would witchcraft not be the worship or practice of committing the deity's work in a way?
It's all very individual and personal. I personally don't do many forms of worship except pray (if you count that) and a daily offering.
Witchcraft is as spiritual as the individual wants it to be. So not everyone who practices witchcraft uses it to worship a deity at all. There are atheist witches out there.
Atheist witchcraft works like witchcraft without calling a deity. So instead of placing emphasis on a God or Goddess, they tend to focus on the elements instead, I believe.