Then follow the rotation of keeping up:
-Rake
-Mangle
-Rip
-Savage Roar
When you have free energy Shred
If you've got 15 seconds on Savage Roar and time left on Rip get a cheeky Ferious Bite.

Use Tiger's Fury when below 20 energy whenever it's up.

Save beserk for heroism/boss taking increased damage etc. Try to have 100 Energy when you use it so you can save Tiger's Fury for after.
References :
I have a level 80 druid Cleared Uldar and all PvE content [always in the top 5 dps of the guild]
Reached 2.1k rating season 5.
Been playing 3 years.

Here is the page with yours
http://world-warcraft-help-guide.blogspot.com/2009/06/feral-druid-dps-rotaion-lich-king.html

Let me know if it was helpful
References :
I have a LVL 80 feral druid