I would have used something more that would blend in and not be so obvious.

Not bad at all for a first dresden.Practice makes perfect.

I absolutely love your Dresden! Great fabrics! Does your machine have a blanket stitch you can mess with? I practice on scrap fabric and find a setting that works with what I'm sewing down. Otherwise, maybe choose a clear thread or something that blends in. Remember, in most cases, no one will get that close to inspect your stitches.

You might want to try shortening your stitches.I know when I use my zigzag I have to go slow and pay attention to the curves in order to keep them in line...I can't remember if you stop your stitch on the outside or inside right before you make your turn..you could try that on a scrap to see..hoped that helped..

I think I would do mine by hand also. A really tiny stitch in a like color won't even show.
Your fabrics are fabulous!! What a nice modern look to an old favorite :D

I just thought of something. Do you have any yo-yo makers??
They have all different sizes and you can do great circles then instead of gathering up the threads all the way just do a little. You would have perfect circles already turned under then you could attach to your plates, then hand sew them on. Just a thought.

I wondered about yo-yo makers when someone else mentioned that's what they do for the centers. I've never even made a yo-yo before. I might have to look into that. Can they be any size?

Clover makes several sizes and they are so much easier than trying to make your own out of cardboard, mylar etc. Right at the moment I can't remember the sizes. I have a miserable cold :(
But I wanted to help :)

What concerns me is that you have such gorgeous plates I would hate to see the centers hurt the beauty. Circles can be very challenging!!

I never put the feed dogs down when I do that stitch. It looks like a zig zag to me. When I use that stitch to applique, I decrease the width and length of the stitch. Go slow around the curves. Use a thread that blends in with the fabric.

Missouri Quilt Co Video uses a yo-yo process for the center circle its fun and easy

I think you need to use a stabilizer behind the circles. you can tear if off later. usually need to loosen the top tension a little for good, close,satin-stitch. use a finer thread on the bottom. use needle-down.stop,(needle down on inside)pivot just a hair,stitch,pivot, etc. I might have this mixed up-maybe it is needle down on outside-try both ways)
do this often. good satin stitch should have a tiny showing of the top color thread "wrapped around" to show a bit on the underside. BLANKET stitch would be easier. some machines need to have it reversed to look right. still need to stop, pivot, etc. Dresden plates are always smashing !
check you machine book for suggestions also.