Let them choose the activity they are interested in and try it for as long as they can without interfering. Even if they drop something, we can sit on our hands to see if they will react and pick it up themselves. When we see that they are struggling and getting frustrated, we can step in and say, “Watch,” and then show them, slowly, for example, how to turn the lid of the jar. Then we can step back again to see how they manage.
