1. Buy your stencils The Stencil Library has over 3,500 designs to choose from, plus brushes, paints and accessories online. Check if the stencil is cut or uncut. Cut stencils are ready to use, but more expensive. Uncut ones will require cutting with a craft knife first.

2. Paint the wall in your base colour and leave it to dry, ideally overnight. Work out how many times you'll need to repeat the stencil across the wall and use a spirit level and tape measure if you're going for a straight-line design. Mark the final positions with a dot at each corner of the stencil. Use spray stencil mount or masking tape to attach the stencil to the first marked position on the wall before you start painting. 

3. Pour a small amount of paint into a saucer. Use a small roller for large designs, and a stencil brush for more intricate ones. Don't overload the roller or brush with too much paint as it could seep under the edges of the stencil. Work from the outside, painting inwards until you've filled the design. Remove the stencil immediately (but gently) and leave the paint to dry.

4. Repeat the process, being careful to follow your measuring marks and making sure that the patterns connect.