Town Hall 9 is all about variety. There is no single strategy that works all the time. To get to be a great TH9 attacker, you have to learn how all the troops behave so that you can use them effectively in war.
As a TH8, you should have learned how to use Mass Dragon attacks as well as Gowipe and possibly hog rider rush as well. It is of the utmost importance that you become good at Gowipe in particular. Not because it will lead you to numerous 3 stars at TH9, but because the intial deployment of golem-wizards and then follow up troops (maybe wallbreakers, maybe heroes, maybe a jump spell) is the foundation upon which most TH9 3 star strategies are built.
Some of our favorite more recent attack strategies for Town Hall 9:
Powerbang showing off Stoned GoBoHo
OneHive Gazette discussing Ground Attacks at TH9:
Balloons!! – Town Hall 9 content around the 4:45 mark of the video.