Update your Saving Throws
Roll your Hit Die twice and take the better result for HP
Add new Skill Points
Add your Favored Class Bonus if it applies
Update your Base Attack Bonus
Update to-hit bonuses for your weapons
Gain any new class abilities
Check old class abilities to see if any of them scale upwards
Learn new spells or extracts where applicable
Gain more Spells/Extracts per day where applicable
Update any applicable skill points, hit points, saves, or armor classes.
Gain a feat.