Here’s an awesome little finger exercise for guitar. I call it “Fretboard Twister,” because it works just like the popular Twister game. Instead of moving your hands and feet to different spots on a floor mat, you’ll be moving your fingers among the six strings on your instrument.
The crucial difference is that you can’t twist your fingers around in a knot like you can with your hands and feet. (Try fretting at fret five with your index finger while holding fret three with your pinky.) This exercise assumes one finger per fret. Find a spot where your fingers lay comfortably, maybe frets 5-8 or 9-12. Challenge yourself later with frets 1-4.
Now you need someone calling out a random finger and a random string. I’ll do it! I made a preset in my Custom Flash Cards app that will do exactly that.
Use the shortcut ‘D’ with your picking hand to deal a new flash card, showing a random finger and random string. Fret the appropriate note with your other hand in the fret range you’ve chosen. Deal a new flash card, and place your next finger without moving the previous one. If the new finger is already fretting somewhere, abandon that string and move it to its new location. Never move any fingers but the one on the current flash card.
Note that there’s nothing to play in this exercise. You’re just fretting notes, not actually playing them. And don’t hurt yourself. Once in a while, you’ll reach a tough configuration, stretching fingers between the first and sixth strings. If it hurts, cheat.