The following is 10 things that I learned from watching Saw I, II, and III:

1. Cutting your foot off is never a good idea. EVER. And, no matter how optimistic we are about it, cutting off a foot and crawling out of an abandoned warehouse will always result in death.
2. Don't ever hire Donnie Walhberg for a part in your movie unless he plays "Angry Cop #1".
3. If you ever wake up in an abandoned warehouse with a message from a sadistic monster, ALWAYS, ALWAYS, ALWAYS make sure that every person in the room with you is in fact, dead as a doornail.
4. People don't change. A self-mutilating drug addict will always be a self-mutilating drug addict.
5. Characters named Adam always have it the worst. Not only are you stuck in containment for 8 hours in a complete shit-hole, you will be shot, forced to beat a guy to a bloody pulp with a toilet cover, left for dead for an indefinate amount of time, only to be... smothered to death. Oh poor, poor Adam.
6. Doll/Clown faces are the scariest things alive.
7. If the tape recorder says that you only have a minute to find an exit, don't spend 45 of those precious second dicking around. Find that bloody key/tip/clue/whatever but don't waste your time doing it!
8. Being Wesley in the Princess Bride just pigeon-holes you for roles. Clearly, the only natural direction for Cary Elwes to take (after being Robin Hood as well) is Dr. Lawrence Gordon, the philandering surgeon. Wesley and Dr. Gordon are like two peas/roles in a pod.
9. Don't hire Danny Glover as the lead investigator in a murder trial. Without Mel Gibson to be his leader buddy, Danny Glover is completely ineffectual. It's all shrugging and confusion and cries of "what do I do?". It isn't pretty. It's all slashed throats and shotgun blasts and Danny, you know you wish Mel would have been there to help you out. Just think of it this way: WWMD? What would Mel do?
10. Sometimes inhabiting places that have zero lighting just targets you as a victim. Save those precious pennies people and GET SOME FUCKING LIGHTS IN YOUR PLACE. And for that matter, get some bloody good locks too. Then that way, killers wouldn't be able to break into your apartments and hide in the shadows. Just a thought.

Ah, all my good life lessons I learned from SAW.