Weak-foot development is not a separate skill. It is a constraint condition applied during game-based practice.
The Principle
Do not run "weak-foot drills." Run normal game-based practices with a condition: "must pass with weak foot" or "must receive on weak foot."
The condition forces development in context.
Implementation
Rondo with condition: 5v2, condition: all passes must be on the weak foot. The game is identical except for the constraint.
Match condition: In a small-sided game, award extra points for weak-foot passes or shots. The constraint is incentivized.
Build-up drill: GK to defender with condition: must pass with weak foot. The game context is maintained while the constraint is enforced.
Weak-foot technical ability develops faster in game context than in isolated drills because the brain learns the weak foot through decision-making, not through repetition.