Lois,
Terrie is so right that your CW quilt will be beautiful and that you should not underestimate your abilities and let your creative juices flow!
Having just been through this before you, I can assure you that a lot of things on my quilt were beyond my experience, but I really wanted to convey what I did. Whenever I reached a place where I did not think I knew how to do something, I just practiced on the side and when comfortable, I moved to the real thing! I also kept to a pretty intensive schedule (easily eight-hour days with lots of breaks to stay fresh), so that when I hit a bump, I was able to take time-out and figure out how to do something and still be on time. Once I had a plan at the beginning of the process, everything did seem more manageable.
So I re-iterate: Lois, you CAN DO THIS!!! I KNOW you can and it will be beautiful! LIke Terrie, I too LOVE your mug rugs and hope when your turn with CW is over you'll consider adding me to your mug rug list!!!