Emerging executive control supports greater autonomy and increasingly adaptive behavior during childhood. The present study addressed whether children's greater monitoring of how they engage control drives executive control development. Gaze position was recorded while twenty-five 6-year-olds and twenty-eight 10-year-olds performed a self-paced task-switching paradigm in which they could proactively prepare for the next task for as long as they wanted before completing it. Gaze trajectories and performance showed that younger children were less well prepared than older children when they triggered the target, even though they could have taken longer to fully prepare. With age, children better monitor how they engage control, highlighting the contribution of metacognitive processes to executive control development.