Hey all, have enjoyed this site for a year or two now - great when I need inspiration!
Like ordinary ski, but bringing both knees up to chest in a tuck position as they cross over; bring hands up to chest at the same time, punch one forward, one back when you land with one foot forward, one back. I say "like you are doing a c-c-ski over your coffee table" and "remember MC Hammer?"
Legs cross as normal; raise arms - reach behind head with one arm to grab invisible horizontal rope and pull forward - repeat with other arm. I say "like the Bondi lifesavers" and "a bit like a big pair of scissors" and (for motivation) "look, Brad Pitt/George Clooney/whoever is drowning - get that rope out to him!"
Start with hands on hips, double-time legs; add arms, punching alternate arm forwards. I say "float like a butterfly, sting like a bee!" and sing the 'Rocky' theme
Star jump (?jumping jack), returning to upright/center, half a cross-country ski, return to center, another star jump, return to center - other half of the c-c-ski, return to center. I say "make a snow storm - more snow - faster - a blizzard!"
Hope that is clear!