Here are some exercises you can practice to increase your left hand's dexterity and coordination on the fretboard:
- Starting at any fret you like, play four notes, one with each finger on consecutive frets. Repeat the pattern 10 times.
- Do the same thing, but change the order of your fingers from one, two, three, four to one, two, four, three. Repeat this 10 times.
- Do the same thing again, but change your finger order to one, two, three, four. Repeat 10 times.
- Do each of the previous three exercises with the order of the notes reversed. Also, try a different string, or try moving between strings in the middle.
- Play notes on the same fret, starting on the lowest string and going up the highest string, then back down again. Do this for all four fingers. See how fast you can do it while keeping the notes clear.
- Starting at the first fret, play every fret going up the entire length of the fretboard. Use one finger per fret. After using your fourth finger, shift your hand up to use your first finger on the next fret. When you reach the top, come back down in the same manner. Try to keep the rhythm consistent.