To sign hockey, hold up the open palm of your non-dominant hand to symbolize the hockey rink. Then form an upside-down letter X hand (or bent index finger) to represent the hockey stick. Swing it inward a couple of times while it hovers above your non-dominant palm, mimicking the stick when it hits a puck on the rink.
Teach your toddler the hockey sign when you are watching their older sibling playing hockey on the rink, or when you are watching hockey on TV or in their cartoons.
This is a useful flash card taught in conjunction with other sports that your toddler is likely to be exposed to or might like to try out when they get a bit older.