I recently designed and painted a sandwich board sign for the Cafe CB1's.
My only brief was to make it colourful and eye catching.
The section at the top on the back was left blank so the owners can write in the Specials in chalk or pin-up fliers and posters for events.
If you're ever in Cambridge its one of my favourite Cafe's so def check it out. Its full of books and they always have really tasty veggie food.