Hi there DKB
First I suggest try washing your towels at 40-60 degrees, using just a little fabric conditioner (too much can cause the towel to become less absorbent).

To make sure your towels stay fluffy and plump, it’s important to reactivate the fibres after washing. If you own a tumble dryer, put your towels in for 5 - 10 minutes (the heat and motion will plump up the towel pile), and then simply hang them out to dry as normal.
I don't own a tumble dryer so I put the towels on an extra fast spin after they have finished washing.

I to save my best posh Egyptian cotton towels and sheets for guests and when my in laws come to stay.
Best wishes for fluffy towels from me DBVC

P.S My Oh and I once stayed in a place that starched their towels and sheets so much they were stiff and worse than sand paper.