Here's some simple rules to follow.
1. Equip yourself with a chainsaw and some manner of fire-arm: Killers in slasher flicks are extremely unlikely to go after someone already heavily armed and will go after the less well equipped 'cliche' characters.
2. Double Tap: The killer is rarely ever dead after being shot/falling from a big height/etc etc. Make sure by shooting them in the head, decapitating them or setting them on fire. There is no such thing as overkill.
3. Don't tell everyone to split up: Use the strength in numbers argument.
4. Make sure the room you are in only has one way in and one way out, as well as being clear of any psychotic killers then set up shop: Hey, one way in and it'll be right into your line of sight. Killer don't stand a chance, neither does anyone else (If anyone else other then the killer is shot by you by accident...well, thank god you have the excuse of 'wasn't me, killer did it!' to use right?).
5. Get the hell out of there as soon as you can via the use of a bicycle or other safe alternative: Killers always seem to target people who go into cars so, hey, use a bicycle. They're silent, environmentally friendly and don't have that pesky problem of stalling on you when you're trying to escape from an axe wielding maniac who's only seconds away.
6. Once it's over, cut all ties to your former friends and town and move country as far away as you possibly can: This is to avoid being killed off in the inevitable sequel.
Follow these rules and you can survive practically any horror movie, supernatural elements notwithstanding.