When in a meditative state you can programme your mind to solve a problem while you dream. For it to work, you have to be sincere about wanting an answer or advice and it has to be something you care about. An affirmation like "I dream useful information or advice that I will understand and that will help me solve this problem" will do.

Here's an example, that will show you that a Freudian interpretation just wouldn't cut it;

...A man was in a jungle surrounded by savages. They were coming menacingly close to him, their spears rising and then descending. Each spear had a hole in the tip. When he awoke he saw his dream as the answer to a problem that had had him stymied: how to design a sewing machine. He could make the needle rise and descend, but not sew until his dream told him to put a hole in the tip. The man was Elias Howe, who invented the first practical sewing machine.

The Silva Mind Control Method, Jose Silva and Philip Miele, Pocket Books, 1977, p55-56