How do I launder towels so they are soft?

Use towels from a very famous store, used to call it God’s own store. They are the softest and maintain their softness over years.

I've got some Horrocks's towels ( bath sheets ) which are a few years old ( bought at Lewis's, Liverpool ) and they've done really well. Probably because they're not an " everyday use " towel, but they have retained their softness and are also good at drying.
They're washed the same as the others in a 60 wash and I use conditioner.

Unless you like a rough towel, like a few of my hand towels, they need replacing. They've been washed to death

My mum always washed new towels before use ?

My mum used to always line dry towels and keep turning them and giving them a good shake. She loved frosty weather for whites as she said if the washing froze on the line it bleached and softened it. We had no tumble drier and her towels were always soft. Me, I use fabric conditioner.

I don't have room for a tumble dryer in my small kitchen, so always have rather rough towels!

I thought you were not supposed to use fabric conditioner with towels as it affects the absorbency. I tumble dry mine when they are almost dry. No room in my kitchen either grannysyb So I have one in the barn. Some people put them in the bathroom.

Yes Luckygirl - 90 degrees!
My towels were hard and scratchy and although like others, it feels like an exfoliation, I felt that they must have a build up of either shed skin or the excess skin softener from my shower cream. The hot wash seemed to melt or dissolve the build up and now they are lovely and soft again - otherwise I would have had to buy new ones (nothing to lose in other words). Quick tumble on a low setting as I felt the hot cotton setting made them hard and a small amount of fabric conditioner to make them smell nice. They are grey by the way and retained their colour! Try it and feed back if it worked for you.

I am trying to save the planet single-handed here! 40 degrees it is for me!

Me too Luckygirl! I didn’t have to buy new towels (again) and I can wash them on 40 degrees!