Challenge five facts and offer alternatives. For example, imagine zippers for securing shoes instead of shoelaces. Examine the factors that may enter into such a choice, such as production costs. Don't be afraid to offer absurd ideas or challenge even the most commonplace concepts; try assuming that the norm is incorrect.
Ask your friends to share their recipes with you, especially dishes that don't match your usual tastes. For example, if you like Italian foods, ask a friend to name their favorite Mexican or Indian dish. Try new unfamiliar recipes.
Choose your favorite short story, painting or song. Add humor and your own style to the piece creating parody. For example, if you're a fan of the Beatles, write down alternate lyrics for "Hey Jude," replacing Jude with a friend's name.
Read three opinion pieces from a newspaper and magazine conflicting with your current political or religious beliefs. Reserve judgment as you take in other opinions. Remain objective until you've finished the articles, and then write a statement arguing or agreeing with the viewpoint.
Search for a book or a website offering a series of riddles and try to solve three riddles a day. Attempt to construct your own riddles.
Think of a problem in your life. Randomly select a noun word from the dictionary and write down ways that object can save you. For example, you may need rent money and find the word "pastry." Brainstorm on ways to start a pastry business or even pay your landlord in sweets. Exercise daydreaming and wishful thinking.