You did a great job. I never get past where I can say I am in my comfort zone. Everything takes a lot of guess work and hard work.
One will not improve and learn unless one steps outside ones comfort zone. This is lovely and I hope you enjoy using it unless your giving away as a present. Keep showing us what your doing and keep enjoying yourself at the same time
Crafter 2243 said exactly what I was going to say. We learn by attempting. I started with designs built into my machine, then designs I downloaded and put on a USB stick, eventually added applique. Then I got digitizing software and learned to combine designs and move things around and maybe change them a bit, add lettering. The one that scared me the most that I kept waiting and waiting to do was Free Standing Lace, but turned out, it was easy-peasy and could have started there! I've probably sewn over 800 items, and only had two errors bad enough to throw away, but I kept them in sight of my machine for a long time. Both were putting designs upside down of how I hooped. One was a bib and the other was a newborn onesie - not an easy thing to hoop. Just have fun!
Still haven't stitched on leather, but know that requires a light stitch design, nothing too dense, and everybody says it is fine. Somewhere along in the list above, I started quilting in the hoop.
Well done. By going out of the comfort zone we learn. I have held my breath many times while trying something new. Your mug rug is adorable. Aren't you glad you tried it?