One of the best exercises I used to get good at guitar was focusing on playing scales and arpeggios in various positions on the fretboard. This helped improve my finger dexterity and ability to navigate the fretboard with ease. I also found that practicing chord progressions and switching between chords quickly improved my overall musicianship and ability to play songs smoothly. Additionally, regularly challenging myself with new and difficult pieces helped push me to improve my skills and become a better guitarist.