Start with the Heart Chakra, then Sacral, then Root, lastly Solar.
Technique: Breathe long slow breaths focusing your awareness on the Chakra being addressed. With each breath imagine that you are breathing “through” the Chakra like it is a portal. With each out-breath imagine anything that wants/needs to be released is being let-go and with each in-breath imagine that healthy vibrant prana is filling the spaces left by the out-going “debris” and charging the Chakra with purity and original vibrancy.
Each out/in-breath bears with it information that may manifest in images, feelings, memories, fragments of thought, notice these but don’t engage them, allow them to inform you of further “places to look” in your meditation practice.
You will know you’re complete with a Chakra when you feel “relief” and a fullness.