These are very well done! If I had to nitpick, and this may be an assumption on my part, you drew them small which means you are utilizing your wrist more than your full arms motion.. While this isn't bad, try and draw larger forms to get that full arm muscle memory. This also helped me make more confident lines, which you seem to already have, but it's a bonus. Keep up the great work, can't wait to see how far you can go!