A few days ago I did something very unusual. I spent some money.
I bought myself a huge black blanket towel along with a matching bathmat and one of those funny rugs that go around the toilet cistern.
I expect each of these items to save me money one way or another. The blanket towel (�28) replaces a couple of mismatched towels that I am currently using. These now reside under my bath where they have insulation value. The bathmats (�10 each) also have an insulation value as my floor is cold.
It is unlikely these items will pay for themselves- but it is possible.