I hunt State land almost exclusively, have been for most of my hunting career. The most obvious (to me), and prolly the most important thing I've learned is to go where MOST other hunters don't, or won't go! You need to be willing to walk that extra distance. It really does make the differance.
The bottom line is, no matter how well you plan things when hunting public land, there's ALWAYS the chance someone will "rain on your parade".