For actual movesets, I'm not entirely certain, but I usually outfit mine with Rock Slide to take advantage of STAB, and EQ to take care of most of the Steel or Rock types that will be switched in because of Sand Stream. It can also learn a variety of other physical moves, so maybe Return? Also, I think that Dragon Dance, now, is a must on Tyranitar, especially a physical one like this. As for Natures, I can't do those to save my life.
So... My suggestion:
Tyranitar @Scope Lens/King's Rock/Leftovers/Whatever you want
-Dragon Dance
-Rock Slide
-EQ
-Filler (Return, etc.)