I'd use this build at level 21. Fill out the following talents in this order:
FERAL Sharpened Claws
Feral Swiftness
Primal Fury
Predatory Strikes
Faerie Fire (Feral)
Savage Fury
Feral Instinct 1/3
Heart of the Wild
Leader of the Pack
Improved Leader of the Pack
Feral Instinct
Primal Tenacity
Mangle
Now you're level 50.
RESTORATION Furor
Naturalist
Omen of Clarity
Now you're level 61 with the cookie cutter build.
Where you put your points now is basically up to you, but I recommend:
FERAL
Survival of the Fittest BALANCE Nature's Grasp Which should put you at level 67 and 3 levels/points left. Either put the three points in
RESTORATION Natural Shapeshifter or
FERAL Primal Tenacity depending on which you prefer: to spend less mana shapeshifting or have a 15% chance of resisting stuns/fears.
It's really a matter of taste, but I personally picked Primal Tenacity over Natural Shapeshifter due to fear effects being so widely used in PvP.
I should probably mention that Nature's Grasp and Primal Tenacity are mainly PvP talents whereas Survival of the Fittest is for tanking as it lowers the required amount of defense needed to be uncrittable versus NPCs.
There are a million ways to put together a build and I just gave one example. Use at own risk.