I've read in a book about Wicca / 'Principles of Wicca' by Vivianne Crowley /, that one of preconditions for the magick to work, is that one needs to really want the magick to work, be determined, disciplined. The willpower is neccessary precondition.
For example, as with Candle Magick - if one lacks the desire, discipline or will to light the candle / as described below / every day for eight days or even a lunar month, there's no point even trying - it won't work.
The proper candle magick requires one to visualize desired effect of magick as if it really, already happened, as one lights the candle, and to speak some verses. The verses can be taken from Vivianne's book, or sometimes it can be spoken heart's desire - as long as it's wise and adheres to the rules of magick / also described in Vivainne's book /. One also needs to work with chakras and energies, making energies flow into one's hands that hold the candle, using the visualization as a tool for controlling the energy flow, and to rub oils into the candle of carefully chosen color. Choosing the proper timing to work the magick is important too. And finally - the sacred space needs to be clean like Temple, and one must ensure that nothing will interrupt the casting - turning off the phone, telling one's roomates to not interrupt one's private meditation moments, etc.
Preparing & ensuring the proper conditions for casting (like cleaning one's apartment, or telling roomates one's need for private moments) are empowering in itself. These 'acts of will' are an important part of spellcasting.
