"Do you ski often?"
Translation:Läufst du oft Ski?
1) The word order you used is wrong, yes, adverbs of frequency usually do not come at the end of a question.
2) Ski is a loanword from Norwegian, and there sk followed by i, j and other letters is pronounced sch / sh. The Duden allows the spelling Schi, although I've never seen anyone use that one. On an interesting side note, Ski is a cognate of German Scheit (= piece of wood).