Main thing about making money in any endeavor is getting yourself "out there." Get your name, what you do, and what you can do for others out to the public. Start networking and talking with other guitarists in your area and anyone potentially involved with music. There is alot of oppportunity out there and opportunities for you to create that you don't even know exist until you find a need for your skills or services. Also, people not even involved in music are sometimes the very people looking for people like you, to teach, to perform, to transcribe, etc. Weddings, parties, birthdays, get-togethers are all oppportunities to show others what you can do (and do for them) and make a little money also.

Besides teaching and performing, one thing that comes to mind is that you could transcribe songs to sheet music for beginning guitarists or guitarists in cover bands who don't have the time to learn a song. You could sell these songs directly to people or in a newsletter or an e-newsletter. In fact, once you have a catalogue of songs built-up, you could sell the catalogue or just on a per song basis. Just an idea. You could write a book on a particular area of guitar or just a book about playing guitar in general - Lord knows I've never seen any worthwhile, comprehensive book on guitar playing explaining basic concepts in detail and putting it all together - ever.

Don't limit your thinking to musicians or guitarists. Everyone enjoys music. Your skills and talent could be used in a lot of ways for alot of people.