Don’t try to teach your Grandma to suck eggs.
Go boil your head
Many a good tune played on an old fiddle
One of my favourite insults Cate 
and when I am feeling really cranky -
You can’t educate pork
(although I know that is not entirely true; pigs are quite intelligent 
‘You can’t pull the wool over my eyes’
Spread oil on troubled waters
The only substitute for good manners is fast reflexes.
Their is many a true word spoken in jest.
I think that this is a relatively new one. If you can’t stand the heat stay out of the kitchen.
In the land of the blind the one eyed man is king
Keeping up with the Jones’s
“You can take a horse to water, but a pencil must be lead.”
Stan Laurel.
The quickest way to double your money is to fold it in half and put it back in your pocket. (my husband)
Blimey, I can’t even keep up with the Simpsons! 
Three’s a crowd
Little pigs have got big ears. (My mother’s favourite when she was gossiping)
The early bird may get the worm, but the second mouse gets the cheese!
Flying is simple. You just throw yourself at the ground and miss
Snug as a bug in a rug
Gordon Bennet!!
I’ll eat my hat!