To sign drill, form your non-dominant hand into a fist, with only its index finger sticking out laterally, pointing to the other side of your body. Then take your dominant hand, form it into the letter A sign, and run it left-to-right and vice-versa, right behind your other hand's index finger.
It is like you are sharpening a tool.
Teach your toddler the drill sign when they are going through a mathematics, sports, or earthquake drill with you at home, in your community center, or at day care.
Teach your child this sign to emphasize the importance of practicing any skill, whether it is physical, verbal, artistic, and so forth.