[header] How to make new towels more absorbent [title] Wash each towel in hot water before use. [step] Dilute the vinegar first or wait until the water level is high enough to dilute it instantly; otherwise, it might discolor your towels. The second wash cycle can include 1/2 cup of, but don't use baking soda and vinegar in the same rinse. 
If your washer has a liquid fabric softener dispenser, put the vinegar in that. [substeps] Note that these are time-proven folk remedies.