Never mix vinegar and bleach. If you use bleach, do it in a separate wash cycle.
How to Use Vinegar to Soften Towels
Wash towels with regular detergent
Add ½ to 1 cup of white vinegar to the rinse cycle
Skip commercial fabric softener
Dry towels completely
Result: towels feel softer, fluffier, and more absorbent.
Extra Tips for Best Results
Use vinegar once every few washes, not every time
Reduce detergent amount—too much soap causes stiffness
Shake towels before drying to increase softness