Always start out with a larger pan than what you think you need. This is probably the best advice I've ever heard to save yourself from unnecessary washing up.
 
A6 card with envelope. Blank inside because what more do you need to say?
 
Why not take the hard work out of sending a birthday card and let me send it for you? Include your personal message and the delivery address and I can send it directly to your recipient! I'll use my best handwriting, promise.