This is the rough outline of what I do:
I start by getting into a meditative state, any method you may use will work here, my way is by counting down from 13 visiualising each number and feeling myself go deeper and more relaxed as it counts down. once I have counted down I cound down from 12, without visualisng them this time (some times I will instead visualise going down a stair case) and feeling myself get even deeper and more relaxed.
Once in that state I start visualising on the root chakra point, I see it a small red ball, I then visualise it opening, like a flower or spiral, opening and expanding with each deep breath. I then visualise it drawing in red energy that fills the body, cleansing it. I then visualise red energy traveling up from that point to the Sacral Chakra, I then repeat but with Orange, and so on through the solar plexis (yellow), Heart (Green), Throat (blue), Third eye (Indigo) and finally to the crown chakra(white), the crown I visualise a large flower opening on the top of my head, its petals forming a crown around my head, then I visualise the energy bursting out from there and its white energy falling like a fountain upon me, clensing my auric field. I then visualise white light coming down and reverse the process closing each chakra.