Tips and Tricks
When jungling with udyr keep track of your phoenix stacks as wasting a phoenix proc can slow down your jungling speed and try to overlap them for large bursts of damage while being conservative with your mana.

If you have blue buff stance dance to keep your passive up at all times.

When dueling save your turtle stance to mitigate the most damage such as Aatrox's third hit or Lee Sin's Q.. If you give the laner the kill tax his lane and push it to deny gold and XP.

After stunning a opponent with bear stance get behind them and move with them while auto attacking.

Team fighting with Udyr is divided into two things.

Diving and Zoneing/Killing the carrys
Peeling for your carries
It's up to you to access the situation and play accordingly.

Phoenix Stance

-High AoE damage
-Gives per second dmg to nearby enemie champions
-On every third hit bonus damage

Bear Stance

-Gives you movement speed
-Stuns enemie champions on-hit

Turtle Stance

-Shields you for a while
-Gives you life steal

Tiger Stance

-Gives you attack speed over time
-The next autohit deals additional damage to anything
-More damage on-hit