This top (McCalls 5388) has become a favourite for me - it offers lots of design possibilities and can be made from either knit or lightweight woven fabrics. The only thing I'm not loving about it is that the little puffed sleeves are finished with elastic in a casing. Shouts cheap to me. Time to change construction methods and gather them onto bias binding.....
First things first, the pattern is the same, there are no alterations. Hem the lower edge as usual then stitch a row of basting stitches 1/4" from the fold.
Tie off one end then gather the lower edge of the sleeve from the other. Measure your bicep and gather according to this. Knot off this end as well. Spread the gathers evenly, keeping the seam allowances at either end flat.
Lie the gathered edge along the centre fold of the bias binding, encasing the edge between it's two layers, and pin then topstitch in place.
This photo shows a close up of the finished bias binding.
Construct the rest of the sleeve as per the instructions.