Catholics used to make the sign of the cross very frequently during Mass. The sign of the cross is often made and said as "punctuation" during a session of prayer. Everyone finds themselves sliding into doing automatic pilot kind of signs of the cross, where they are rushed and not really contemplated. Here is an exercise I recommend, especially for children.
When you touch your forehead saying, "In the name of the Father," think of how the head represents God as the parent. When you touch your abdomen and say "and of the Son" think of how that is the position where one might be cradling a child, such as the Holy Child Jesus, and then as you touch each shoulder saying "and of the Holy Spirit, Amen," think of how the Holy Spirit often appears as a white dove, and each shoulder is a wing.
This adds a simple profundity to the sign of the cross, slows it down and makes it less automatic and for children it makes the sign of the cross and the Trinity much easier to understand.
Hope you find this exercise useful.