Before filing a patent application, you should document the invention. In addition you should determine whether the invention is in fact patentable and whether patenting makes sense.

1) Documenting the invention. Details related to the conception (mental realization) and reduction to practice (successful completion) of the invention should be maintained by the inventor(s) in a bound or consecutively paginated notebook. Each page of the notebook should be signed and dated by the inventor(s). Preferably, each page should also be signed by at least one other person, who is not an inventor, but understands the invention, is obligated to confidentiality and would make a good witness if there were ever a dispute about when, how and by whom the invention was made. Electronic notebooks can be used as well, so long as entries are recorded with a date.

2) Determining if the invention is patentable. An invention is patentable, if it is directed to appropriate subject matter (process, machine, manufacture or composition of matter); has at least one specific and substantial utility that is credible; and is actually "new" and non-obvious.

3) Determining if patenting is appropriate. Even if an invention is patentable, patenting may not be appropriate, for example, if the invention does not have sufficient commercial potential to merit the costs and effort involved or if the invention would be better kept as a trade secret. (A trade secret can last as long as the invention is truly kept a secret, although it is not an easy thing to do in practice.)