I was pointed to Live2Detail.com after reading several detailing posts on this forum. Check out the Ask A Detailer thread here. Some tips that I can remember:
Wash microfiber stuff by itself, don't mix in with other types.
Wash before first use to get rid of anything embedded in the towel (yes, even though new). Also helps it fluff up and work better. I think hot water setting is fine for wash.
No bleach or fabric softeners. There are various MF specific detergents available if you want to try them, $8-$10/16 oz. Generally, takes 1 capful for light to medium loads and 2 capfuls for heavy loads.
Dry until lightly damp and hang on rack for final drying (ideally). Just don't use an extended or HOT drying cycle.
Apply minimum pressure to surfaces to get job done. Work in straight lines. Do not "scrub" with towel (on painted surfaces anyway).