Trappers & Blockers
Trappers and blockers only come in 4 sizes: youth, junior, intermediate, and senior. Because of this, fitting is fairly simple. Have the goaltender put a blocker glove on their hand and turn their palm to the sky. Pinch the ends of the fingers to feel for the gap/growth room. There should be no more than a pinch of the fingers. Any more room and the goaltender will have difficulty holding the stick. A quick test for room is to place an un-taped stick on the ground and ask the goaltender to pick it up. If they are able to do it without difficulty, the blocker fits. Once you have found a blocker size that fits, the corresponding size for the trapper will also be correct.