How can I make a spooky Instrumental on FL Studio 9 Fruity Edition?

I need to make a few spooky-ish songs for a film I am making. Because no-one would give me a direct answer on where to find people willing to help for free, I have now resorted to doing it myself. My music teacher always said dark songs much be in the Minor key. I get that. It must also have a deep b. But I have no idea for the layout of the b as everything I do on there sounds like retarded burping. PLEASE WILL SOMEONE GIVE ME A FULL AND LOGICAL ANSWER?