A great way of maintaining your fretboard knowledge is to put yourself through a simple exercise at regular intervals for short periods of time. By limiting the time you have to concentrate on any one thing, it has been found that your memory will work more efficiently. In short, little but often is much better than once for a long period of time.

Set a metronome to 46bpm and call out any note at random. Play that note on each string, starting with the 6th and working down, on each click of the metronome. If you miss one out or hit a wrong note, start again until you play all six locations of that note correctly. You will know immediately if you have hit a wrong note because your ear will be tuned in to the note you started with.

When you can do this comfortably with any note at 46bpm, speed up the pace to 60bpm. Start off with the easy ones first (A, E, G, etc) and then try to use the accidentals with both the sharp and flat names (Bb, G#, F#, etc). Open strings can be used, as can the notes on the 12th fret, although try not to rely on them as a solution every time; that would be too easy.

Note: This is NOT a speed test! Your mind will work more efficiently if you stick to 60bpm and practice this exercise for no more than 10 mins. It is also a lot of fun and you can put your friends on the "hot spot" and see how they get on. You will be surprised how much trouble even the most advanced players can have with this method.