This post was written by one of guitar instructors, Chris Evans. Chris has over 30 years experience in music education and is a dynamic communicator and teacher. Here is a gem of a post he's written to help those of us who are DIY'ers.
1) Play a lot, or at least regularly. Put your guitar on a stand in your room, so it beckons you to pick it up!
2) Play with others. If you are more advanced than them, you will show them stuff and reinforce your own knowledge. If they are more advanced than you, you will learn new stuff. If you are on about the same level, you can explore new music together, and have some real fun.
3) Listen to a wide variety of music styles - beyond pop! My suggestions include: blues, jazz, classical, folk and world music. And try to pick out the instruments and rhythms used, or the mix of music styles.
4) See artists in concert. Again, from various genres of music.
5) Try to learn songs by using your ear only - no song charts. Or even just a neat riff in a song.
6) Just jam on your instrument by yourself - make nice-sounding notes, chord patterns, strums etc. Learn how to improvise - just keep trying, and trust your choices of notes. If you don't like some, stop and find some that work better to your ear.
7) Try to write your own songs. Look for inspiration anywhere and everywhere, by keeping a creative eye on the world around you.
8) Experiment on your instrument! Try different or odd chord progressions, add taps on the body, muting of strings, mixing chords with single-note lines, sound effects with pick or voice, etc.
9) Find songs with chords you don't know - learn one new chord a week and use it in the song.
10) Try other instruments whenever you get a chance. It helps in understanding what different instruments can add to a song or a concert. Be brave, just try them, learn and laugh!
11) Go to music stores with other musician friends. Poke around, talk with staff, ask questions, learn about various instruments, the companies that make them, the different models they make, etc. Just make it an enjoyable field trip. Stay for and hour or so, dig in. And have fun!
12) Regarding the songs you have learned. You have to play them now and then, to keep them in your memory and keep them lubed. Make proper songcharts for each one, and put them in your songbook binder in the plastic sheet protectors. And keep a folder of the song docs on your computer, in case the songbook ever gets lost. And play them for others! And with others! Teach some others a song, and play it live at an open mic night, or even just for friends at a party. It gets easier to play live every time you do it. You get some good feedback, you begin to get comfortable, and then it becomes big fun!