| I prefer a combination of shapes and notes.
I started by learning the shape of a scale in one position, along with all the notes of the scale, then I learned the extended shape of the scale (how the shape connects to other notes of the scale outside of the single position). I moved on to more scales from there. Finally, after learning extended shapes and many scales, knowing all the notes up and down the entire fretboard has become pretty automatic.
I think it can be useful to know both (at least before you have completely mastered the instrument and everything is nearly automatic). One can be useful in a certain situation while the other can be useful in others.
What helped me learn all of this quickly was to practice the shapes and note positions every day, not matter what, without fail. A minimum of 30 minutes per day, but more will help. You'll find that your learning becomes exponential if you stick with a very consistent practice routine. Oh, and don't forget to keep your routine musical and as interesting as possible, you don't want to spend too much time just running up and down scales purely for the purpose of memorizing them. |