When it comes to , small changes are a good start.

"If you try to downsize your house, get rid of all yours cars and make all of these drastic changes, it's so overwhelming and you're not going to do any of it," says self-made millionaire Chris Reining, who banked over half his income to retire at age 37.

"The will lead you to be able to make the big changes."

You could start by saving on toothpaste, for instance.