Microfiber towels do not like heat. For best results wash in cold water with NO laundry detergents and NO fabric softeners, instead use a dedicated microfiber detergent. If using the dryer make sure you use the low heat setting.
This is what I do (from owner Craig Schmidt)
I use one part white vinegar and one part dedicated microfiber detergent (Micro Restore) and hand wash my towels and air dry. When I have a big load I use the washing machine and low heat tumble dry setting.