Start by downloading and printing out this stencil template. Then, trace the design on to a piece of freezer paper (or acetate). Next, cut out the design using a craft knife, creating a stencil.
To prevent the stencil from shifting as you work, use masking tape to secure it to your lampshade. (If you're not using an existing lampshade, Lotta recommends purchasing the most inexpensive plain cotton or linen lampshade you can find.)
Load up a flat-topped stencil brush with blue acrylic paint, dabbing away the excess. Next, using an up-and-down pounding motion, apply the paint to the stalk and leaf motifs of the stencil. Rinse your brush, then use the same technique to fill in the yellow flowers. For the brown centers of the flowers, Lotta used furniture protection pads. They are sticky on one side, so you can simply plop them wherever you like.
Adapted from "Handmade Living: A Fresh Take on Scandinavian Style" by Lotta Jansdotter.