To start find yourself a good image to copy from, here I've chosen an old penny, photocopy and enlarge it. I've then drawn 5mm squares over the drawing which will help me enlarge the picture. 

On a larger piece of paper I've drawn 50mm squares and copied the portrait. This will make the large drawing ten times bigger than the original. I have shown this by including a finger rubbing the Queen's Nose (now where have I heard that before)

Because there is no colour on an old penny I had to research to find the colour of the Queen's eyes, her hair and all the many precious stones on her diadem (small crown) and around her neck. Here are the small sketches I made before attempting the signboard proper. 

The sign is a swinging board type so it had to be painted the same on both sides. The board was an original and had been painted many times before. I stripped it down to the bare wood and whilst doing so came across at least four different Queen Victoria's. The frame was oak grained and the whole coated with yacht varnish.