Is there an aspect of your favorite hobby that you could write about? One great thing about writing about your hobbies is it is easy to find and reach the market through magazines, mailing lists, etc. If you’re new to a hobby and are learning about it, this could be a good opportunity to write a beginner’s guide to a certain hobby. Then, once you are finished you will not only have the basics down, but will have a finished book ready to sell and told from the perspective of a beginner.
Is there a hobby you have always wanted to get into but haven’t found or couldn’t justify the time? Now you don’t have to feel guilty. Get into the hobby and write about it.
Study the market of the hobby you are interested in. Check the Internet newsgroups and message boards. Is there a recurring demand, need, help or want? Get a feel for the market. What kind of book do you think they would want? What problem needs solving?
Here is a partial list of hobbies you might consider writing about, getting into and studying further: astronomy, birding, candle making, dumpster diving, gardening, home brewing, kites, remote control airplanes, magic, photography, rockets, trains, woodworking, rocks, models, soap making, treasure hunting, sewing, beading, ceramics, painting, leather work, wine making.