Beast Mastery Hunter relies on the pet to do most of its damage, works quite well for leveling and mid game, however it falls off at end game and becomes a low tier DPS.

Rotation for Beast Mastery Hunter Wotlk

Beast Mastery Hunter Rotation and Priorities

Hunter’s Mark (Keep debuff up) > Serpent Sting (Keep debuff up) > Kill Command > Arcane Shot > Steady Shot > Spam Kill Shot on low Health

Tips

Get to know the fights to pop cooldowns at the best times (low movement, no crowd control, AOE damage, etc).

Time cooldowns so they can be used to clean thrash and be ready at boss fights.

Use Volley and Multi-Shot in AOE situations.