Pouring water from a cup
Get 2 buckets. One bucket is full of water, the other is not. Get a good size cup, and fill it with water with the bucket full of water, then pour it to the empty one. Keep doing this till you feel any tiredness with your left hand. By the way, if your empty bucket gets filled up with water, you can pour it to the former bucket full of water to make it full again using the cup, then repeat. The goal of this exercise is to coordinate your left hand
