Don't put new wine into old bottles
Don't rock the boat
Don't shoot the messenger
Don't spoil the ship for a ha'porth of tar
Don't sweat the small stuff
Don't throw pearls to swine
Don't teach your Grandma to suck eggs
Don't throw the baby out with the bathwater
Don't trust anyone over thirty
Don't try to run before you can walk
Don't try to walk before you can crawl
Don't upset the apple-cart
Don't wash...