Mechanical filtration media:
Rinse thoroughly in a mild chlorine solution.
Rinse thoroughly in tap water.
Soak and rinse thoroughly in tap water to which a dechlorinate has been added.
(Please note that I utilize "so much of this media" that I perform this algorithm via my washing machine and dryer) Biological filtration media:
Rinse a bucket out with tap water, empty and dry.
Siphon tank water into a bucket.
Remove the biological filtration media.
Rinse the biological filtration media in the bucket of tank water.
(Please note that I do this via the sump in my wet/dry system with the return pump off and then evacuate the sump prior to turning the pump "back on".)