I strongly recommend the book Landis on Mechanics of Patent Claim Drafting, by Robert C. Faber (Ostrolenk, Faber, Gerb & Soffen). This reference covers drafting claims for every type of invention. Don't bother to study the entire volume, though. Just pay attention to those sections that deal with your type of invention. It will really help.

One note of caution: make sure you spend some time and effort on the drawings. I always do my own. The Patent Office is very strict about them, and its standards for them can be found at http://www.uspto.gov/web/offices/pac/mpep/documents/appxr_1_84.htm.

In particular, make sure you always use the same reference numbers for all the elements in your drawings. That is, if your patent uses, say, a particular "circular restraining widget," then decide on a reference number for it and use that number wherever the widget appears.

After filing your application, don't be too discouraged if the examiner rejects it. If the rejection is based on an earlier patent that is identical to yours, there isn't much you can do. But if you feel there are significant differences between your invention and the one cited by the examiner or if there are other reasons for the rejection, you have several options.

If the examiner claims that your application is "nonenabling," that is, that you have not described the invention in sufficient detail for an ordinary worker "skilled in the art" to make or use one, you can simply file another application with the details filled in.

Another option is to file an appeal. I have six U.S. patents: 6959050, 6019393, RE36455, 5525060, 5159322, and 4949079. The first two patents were awarded only after I appealed to the Board of Patent Appeals and Interferences. (Patent 6019393 is for credit card slips in a restaurant; it allows you to indicate your gratuity as a percent of the bill, instead of an absolute amount. Really.)

Getting patent 4949079, for a special type of scanning device, was even tougher. I had to file an appeal with the U.S. Court of Appeals for the Federal Circuit after an appeal to the Patent Office of an initial rejection failed. I appealed pro se, and ultimately the patent was reissued. Frankly, I found writing the appeal briefs enjoyable. And I saved tens of thousands of dollars in legal fees. Had I not appealed, I would not have been awarded those patents and that reissue, so don't be afraid to lodge an appeal yourself. If you can think logically and marshal your arguments, you can file appeals—and win. But that's a topic for another column.