Are your brush strokes overlapped and messy looking? You're not alone. Many beginners suffer from this issue. To improve your technique, you'll need to practice making large strokes and using careful edge control -- which is exactly what this exercise was designed to help with. Look for the worksheet downloads at the bottom of the post.
Do you have any tips for accomplishing this assignment? Was it harder or easier than you predicted? Let's hear about it in the comments! And finally, remember to have fun drawing.
Assignment: Copy the (attached) rendering samples.
Things to consider: "Temp Layers", smooth rendering, edge control.