I'm trying the new Sewy bra pattern at the moment and am very impressed by the way this bra is finished on the inside, working along the instructions given. Of course I do change a few things here and there, but the instructions are overall very clear. The only mindor dislike is that you see a partially stitched seam in the illustration, where they mean that the whole seam must be sewn. This was a bit confusing at first, but now it's clear, no problem any more.
This pattern is designed especially for non-stretch fabrics and for the larger cup sizes (if I remember well there are 4 size-groups to choose from, and my D75 is in the first group). The cups are therefore interfaced. You sew the cup-parts in 3 layers on each other, folding them back gives a very neat finishing on the inside. This you can see in the last picture.
The instructions tell you to do the following in two steps, stitching twice. I did it in one go.
The lower cup facing is pinned to the wrong side of the upper cup, then you pin the right side of the lower cup to the right side of the upper cup and stitch the seam.
Then trim the seam allowance, fold facing and lower cup together and topstitch.
These are pictures from the outside and the inside of the cups.