I don't keep count, but when I see the players rolling for the season (including seasonal experience), it tends to be the their or so three core runes, two to three Passions, and maybe 10-15 skills, including 3-4 combat skills (note that I allow ticks for all skills, though). And 95% of the time, a POW gain roll.
Just tell them they don't get the tick if you think a particular skill use is a pointless stretch that just wants the tick. This will quickly establish the norm. But even if a player's use of say Dance, Sing and Darktongue to impress some trolls is actually just intended to earn ticks, that's not a problem if the outcome for play is good.