Practicing just downpicking is a better way to get better at it because it builds strength, endurance, and precision in your picking hand. When you focus only on downstrokes, your hand has to work harder than with alternate picking, which helps develop the muscles and control needed for tight, aggressive rhythms—especially in rock and metal. It also forces you to lock in with the beat, making your timing more solid and your playing more consistent. By isolating downpicking, you eliminate distractions and can focus purely on technique, helping you play faster and more accurately when you eventually apply it in full songs or mix it with other styles.