Author: Ted James House flipping is a good way to make money post-retirement as well as a worthwhile use of your time. The return on investment can be a respectable 10 to 20 percent, reports NewSilver, which comes out to profits of $15,000 for a $100,000 house and $60,000 for a $400,000 one. Did we mention you can be your own boss and live out your dreams of being an up-and-coming business...