Top tip number 1!
Try and think of all the normal people you know. Can't think of any? Exactly! If they're all crazy, well, bingo bango bongo - that makes you the sane one.
Top tip number 2!
Read fiction. You may momentarily believe you are in fact the characters you're reading about, and if they're all sane then, hey presto, looks like you're sane too.
Tip top number 3!
Buy a scented candle. Sometimes the flame is so mesmerising you can stare at it and forget about everything that exists in the world. Ergo insanity doesn't exist. Ergo you're sane. I mean you use 'ergo' instead of 'therefore' - you clearly have your shit together. Side note: The scent aspect is simply to justify always lighting candles and a good alternative to staring at gas hobs.
Top pop number 4!
Wear flat shoes. Nothing screams sanity more than good arch support.
Tit pap number 5!
Act overtly crazy as a double bluff.