It's a form of sympathetic magik, meaning it works on the principle of cause and effect. (As above, so below) That kind of thing.
It's cycle is Birth....Death....Rebirth.
The birth of a desire/need.
The death of it here on the physical plane....i.e. sending the rite to the astral/spiritual plane.
The rebirth on the physical plane as the rite manifests itself. In this realise that the cycle will continue and most things are only temporary.
Direct your intent to "the source". Whatever your belief is. This is where colours and timings can come in. Some people prefer to direct their rite to a god/goddess etc. Planetary influences e.g. Jupiter for learning etc. I see these as intermediary energies. They may serve well in sending your intent to the source but I believe that is where it needs to go for the rite to manifest itself, not to an intermediary. The centre/beginning/source of all universal energy. The creator if you like, where all things came from and all things are connected to and all things will return. Using an intermediary is your choice, it's your rite. I prefer to focus on the source, I'm not very religious with the craft. Whatever feels right to you is best.
Transform your intent from material/physical plane to astral/spiritual plane using the element of fire to reach "the creator" a God or Goddess, whatever feels right to you. The rite needs intent/direction i.e. just burn the candle while focused on your intention.
I feel this step is often missed, you must believe, without any doubt, that the rite has worked and has happened. This is the manifestation of the intention onto the material plane. I suppose you could say the law of attraction plays a part in CB.
Note: be careful what you wish for, the source has a great sense of humour! (broken leg, money etc.)
I have found that the less complicated it is the more success I have, back to 99% will and 1% props again. This does not mean that the CB in itself is almost not necessary, it is to point out the importance of your own will. I have also found that it is better to go with your gut instinct than follow someone else's rites.
Again....
"Magik is the art or science of causing change to occur in conformity with will." Aleister Crowley.
"The Magician's Tables: A Complete Book Of Correspondences.", Alan Richardson.
"777", Aleister Crowley.
"Candle Burning Rituals: A New Guide To An Ancient Art", New Age Fellowship, published by Finbarr.
"Advanced Candle Burning Rituals", Raymond Buckland.
"The Complete Book Of Incense, Oils And Brews", Scott Cunningham.