Learning another language

I see from looking on language job websites when researching for http://languagejoblink.blogspot.com/ that such jobs can earn £20,000 to £50,000.

Sounds like those jobs can seriously improve your earning power.

Attending your local language course can be a first step to that well paid career.

Fitness training for the elderly

You could set up a fitness for retirement/retired people,its a massive market potentially worth millions.

Potential customers include retirement homes,which you could contact with a brochure.

Potential earnings could be £3-4,000 a month.

You will need to employ teachers for which you can advertise.