Towels and many other clothing with washing loss quality, loss softness even you bought expensive.
There is a trick that will return the shine with one washing.
The first tip is to not put too much cloth or towels in the machine because can’t wash well.
Put your towels into the washing machine and add a half cup of vinegar. Vinegar will give on your towels softness, but also will clean up your machine and kill unwanted smells congregating in it.
After you wash your towels in vinegar start the machine again but this time wash with water.