Fingering the frets properly is one of the most difficult and most important skills that any guitar play must develop. There are any number of variations of these exercises. The important thing is to get used to using all four fingers in a systematic way. Work on drills like this to strengthen your fingers and develop accuracy. Here are some points to work on:

• As with scales, you should practice while not looking at the fretboard.
• Keep the fingers arched and don't touch adjacent strings.
• Finger each fret up close to the fret wire.