Source: K. Anders Ericsson; Peak (with Robert Pool)
Focused, effortful practice on specific weaknesses just beyond your current ability, with immediate feedback. It differs from simple repetition, which tends to plateau.
When to use it
Use it when you have plateaued at a skill you already use regularly.
How to apply it
Break the skill into specific sub-skills.
Pick the weakest sub-skill to work on.
Design a practice task slightly beyond your current level.
Get fast feedback from a coach, expert or objective measure.
Adjust and repeat in short, fully focused sessions.
Tip: It is tiring by design; keep sessions short rather than trying to sustain it for hours.