- Take formal lessons from a qualified teacher. Be sure to seek testimonials and references.
- Watch others play. Notice what they have to pay attention to and what seems like magic.
- Practice arbitrary scale runs. Go up and or down 3 or 4 notes and then move up the scale with the same interval.
- Jam up with friends who are better than you as frequently as possible
- Get some friends along who are at the same skill level and form a band of your own
- Listen to your favorite music and try to envision what the guitarist is doing to make the notes come out as they do.
- Listen to different music. It may open your mind to techniques and phrasing you never imagined using before. It may also expand your musical library. Pick any genre you're not familiar with. Get a feel for the timing and note choice. Into classical? Try bluegrass. Headbanger? Pick up some jazz or blues. Then move on to your hero's heroes. Find out what musical influences got Jimi Hendrix, B.B King or Eric Clapton primed for stardom.
A great way to continue learning if you can already play is to teach guitar to other people.