A formal background would be nice, but like what most of us would agree, there are no lutherie schools here in the Philippines. The best way, at least as a start up, is to work on your guitars, or some cheap guitars that you would like to learn on. Do some guitar projects. Working with electric guitars, like set ups, change pick ups and other parts, can get you off to begin. Getting books like that authored by Dan Erlewine, are great guides. The internet would have a lot of guides and directions on basic set ups and what have you. But be careful to follow and selective on what is really the right way of doing it. If you have the chance of going abroad to study, even for just a short seminar, it is an asset. But start somewhere. Get some tools for set ups, i. e., action adjustments, changing pups, parts, etc., exchange ideas with guys who can give you a tip or two. Study the requirements and characteristics of each type of guitar, whether Fender, Gibson or whatever. There are books and magazines as well as the internet as sources of info for these. When all else fail in your quest, you can always bring your guitar to better techs like Mike Sison, etc. The important thing is to start somewhere and understand what you are doing and how things work. It will be easy to do things later on once you know all these. I started this way and I set up all my guitars. But when one of them needed its truss rod repaired, MicSis was the answer.