Keith's top ideas & tips
Hold a bring-and-buy sale.
Charge more for expensive and newer-looking items.
Sell car washes.
Charge more for bigger vehicles.
Hold a people-auction, where people donate their services.
Persuade people to donate the use of their belongings as an added bonus.
Sam, from Tywyn in Wales, washed nearly 20 cars in four hours and raised £111.
That could transform the lives of four families living in the slums of Kenya by giving them regular access to clean water.