tips for being a better jungler (amumu)

I started playing a lot of amumu recently. I think he's a really fun champion with the capability to turn team fights into your favor. I'm pretty new to jungling. I start out with hunters 2 HP pots and a trinket. Most of the time at the beggining of the game, I'll steal their junglers opposite buff which is usually undefended. Then I'll get my blue using my 2 HP pots. Then wolves. Then back. Now I clear out the camps around the red buff. From here I randomly go around my jungle, getting crabs, etc. At 6 I'll gank botlane hopefully giving my ADC a double. Most of the time I'll grab drag after a successful botlane gank. Are there any tips you guys could give me? Anything I'm doing wrong?