Shady cottage garden designs like this are some of my favorites. They have such a woodsy, tranquil, old world atmosphere. Because of the tree cover, consideration has to be given to the plant selection to include plants that will do well in the shade. In this design, there's not a lot of emphasis on color but more on different textures and shades of green. Keep that in mind when creating your planting scheme. You can create combinations of different textures and shades of one color as well as color combinations. See color theory for garden design plants for more on this.
One more thing I'll point out about the plants in this shady cottage garden front yard is the use of white plants. While it is usually most tasteful to use it sparingly, anything white mixed among all the green, including plants and decor, will create a natural focal point. See landscaping focal points to find out more about creating focal points in your landscape and garden design.