Rule 1: Don't Eat The Local Cheese
Unless you're sure it's the local cheese, don't eat it. Trust us.
Side effect: Unfortunate Food Poisoning
Rule 2: Bring A Map
Don't get lost in the multiverse. Bring a map, or at least a compass.
Side effect: Universe Cartography
Rule 3: Don't Trust The Guidebook
It's not a guidebook, it's a liebook. Don't believe everything you read.
Side effect: Universe Deception