The Main Tool to make a spell work is yourself, you dont need candles,oils,herbs etc...
In my opinion to make a spell work it depends on your connection to divintiy and what you believe and what your experience is.
what i mean by divity is by will,thoughts,feelings, and exresiions.
Casting a spell:
Dont forget to set your goal.
Prepare your spell on how you are going to cast it.
Also many people say they cast "white magick" and "black magikc" spells well to tell you the truth, all magick is the same and it has no colour people just use a label for it. like they say black because they use it for bad stuff and people say white to use it for good stuff, magick is only your intent.
If your beginning spell casting i suggest learning the basics. this link should start you off.
I hope this helped you out a little bit.