There are a few companies (Sleevey Wonders, Sleevey Magic, EZ Seeves, Sassie Sleeves and UK based Cami Confidential who also do some great high front lace camis) making a modern version of a sleeve+bodice to wear under a sleeveless dress idea which I suspect goes back to the medieval chemise.
Anyway back to the modern version, where the idea is that you can wear something under your sleeveless dress to give the appearance of it having sleeves. Versions in mesh or stretch lace look quite interesting. To get the best effect these seem to have no shoulder seam and no seam on the upper edge of the sleeve, a deep scoop neck on one side and a deep V with clasp on the other, to avoid too much fabric pooling under the arms a variations on the Close Fitting Kimono Block looks like it would work quite well.
So here's my mini mockup of what a 'sleevey' might look like.
Anyone else tried to sew their own 'sleevey'?
If you don't mind a seam where the sleeve joins the body then just use any close fitting knit top pattern, scoop the neckline out low front and back, use the selvedge of the stretch lace as the sleeve hem and finish the neck and hem with fold-over-elastic (FOE).