There are "entrepreneurial" kinds of things like becoming a seller on e-bay, or in a similar vein there are stand-alone companies that let you design T-shirts, mugs, etc and use their software to create an online storefront -- but then it's up to you to promote it, give out business cards, advertize it, etc.
Apparently people make money even from stuff like thinking up new ideas for that "Keep calm and carry on" slogan for t-shirts and coffee mugs, thinking up new variations, like "Keep calm and think about George Clooney".
Of conventional jobs, the people I've known who worked from home seem to have been people in some kind of IT related field, who had been working at the corporation offices but then got to move into working from home more and more.
I know someone who is an editor for the website literature of a major charity entity. She edits other staff's articles about their latest projects and fundraisers.
I'm not sure but I think some types of call centre work/customer service work for an existing company can be done from home; you would have to get set up with a headset.
I don't know about the UK, but in the US there was a small airline who employed customer service people who worked out of their homes.
If you know any other languages, I knew a woman who taught English as a second language to foreign students, and company that provided these teachers used Skype as the way the teachers and students had their lessons.
You could google on "customer service jobs work from home" or ESL work from home.