It's a Bird, It's a Plane, It's...My Fingers!
I remember at one time my fingers used to fly about uncontrollably over the fretboard. I'd press with one finger and the other three fretting fingers would fly off as if trying to leave the room.
Almost all of my students have this problem early on. It's very normal. But, it's also very inefficient, and it's something to fix if it's still happening to you.
The further away your fingers are from the strings, the longer it will take for them to come back to the strings to do anything. This will slow you down. It will impact your legato—long and connected—notes. Overall, it makes things sloppy.
The Sustained-Note Exercise Concept
When I realized how inefficient my flying fingers were, I created these sustained-note exercises for myself to correct the problem. I've been giving these simple exercises to my students for years, and it has helped them get control over their fingers, too.
The basic idea of these exercises is to let one finger hold and sustain a note while the other three do something else. You are trying to keep one finger down the whole time.
By sustaining the note, you will hear it stop ringing if you pick it up. This gives you audible feedback that you're doing it right (or wrong).
These exercises require you to listen and concentrate. Play them very slowly. Speed is not a goal here. It's all about coordination.
WARNING: Only play these exercises high up on the fretboard like the examples on frets 9-12. Lower frets are too big of a stretch for these exercises. You can even move them higher if that's more comfortable for you.
It is easy to overdo it with these exercises. Don't play them for too long at a time. Strive to keep your hands relaxed. Many musicians get hand injuries by repeatedly stressing their hands. If anything hurts, stop. If it really hurts, see a doctor!
The Four Sustained-Note Exercises
There are four exercises on the exercises page—one for each fretting finger.
1. Starting with the fourth, pinky finger, you will pluck and hold down the note G on the 12th fret. Then, while sustaining that note, play B, C, C# on frets 9, 10 and 11 on the D-string using fingers 1, 2, and 3. Never pick up your fourth finger.
2. The next exercise is similar, but uses the 3rd finger to sustain the note F# on the 11th fret of the G-string. Play the sustained note followed by B, C, and D on frets 9, 10 and 12 of the D-string.
***This has added difficulty of not muting the sustained note on the G-string with your 4th finger.***
3. & 4. Just like the previous exercises, sustain a note with fingers 2 and 1, and use your other fingers to play notes on the next string. These are also harder because you have to avoid muting the sustained note with your other fingers.
I encourage you to make up some similar exercises, or write some original basslines which challenge you.. Find things which frustrate your fingers and fix them.