I made some little dresses for my niece for last year’s Christmas, and adapted the design to make a little top and matching leggings now that she is a little person running around.
I started with roughly the same dress pattern I had used before, from this website. But I traced around the bits I wanted, but made it several inches shorter. I also drafted some little sleeves (bit fiddly, but basically semi-circles that got ruched), and a strip to make a floaty ruffly bit at the bottom.
I used white double stitching around the hems as a contrast. The neckline was the hardest, and consequentially messiest bit. Initially I was going to just have a button on one side but decided it would be too hard to put on so I had to do some hasty changes to add a button to the other side. Button holes still not my strength! And I couldn’t find bias binding in the right colour so I made my own from spare fabric, which worked but the edges of it ended up being a little scruffy!
The matching leggings were pretty simple, I got the pattern from here and again used double stitching around the hems. The fiddly part here is that the jersey stretches when you sew it and slips about under the sewing machine foot so the stitching went a bit wiggly.