Ever made that cool muted sound where you lay your left hand fingers across the guitar strings? That’s “thunk” practice.
For the Right Hand
Try just laying your left hand across the strings, muting, and play any right hand arpeggio pattern. This is a great way to hear and correct any rhythmic unevenness in the fingers. It works great while changing note durations to achieve a more even, consistent rhythm.
This works best with repeated patterns and is solely for practicing right hand things. The second method is more about the left hand.
For the Left Hand
Another good way to use thunk practice is to the play the piece as normal, but don’t actually apply any pressure, just let the fingers tips rest in place on the strings. Be sure to strive for super accurate placement–left hand finger tips right behind the frets, etc. If there’s an open string just let it ring.
This produces a great feeling of lightness in the left hand which carries over to the next time you try the passage normally. I’ve been using this technique a lot on a particularly challenging section of Bach with a lot of bars and awkward position shifts. It’s a great way to get rid of excess tension in the left hand.