When my son was still very small we made what we called a HISSY-FIT TOOL BOX. We chose a hinged, aluminum box from among his playthings, and then sat down together and filled it with about 20 slips of paper upon which we wrote the methods that we thought might calm him down in a rage. The contents have changed over time, but the box has been very useful, not only for the ideas it held, and holds, in a moment of crisis, but for the self-awareness and discussion it has provoked between us.
The slips of paper would be very individual to meet a child’s needs. Today, playing one of his instruments is a method of calming; years ago we didn’t have that alternative. When he was younger I made him smash a bed with his fists; and that’s unnecessary today. Also, he now has karate ‘katas’ to perform in an overcharged moment; we didn’t have that when he was four. Might this work for you? What methods might be appropriate and ‘doable’ for your child?