I pinned the sleeves with right sides together. I drew the cap and cut both at a time.
I basted the sleeves to the garment body and sewed. You can see the waves at the shoulder - the sleeve should be slightly gathered at the upper part to fit the arm well, but no wrinkles are allowed!
The dress is almost finished, the only ugly thing is the lower hem. I marked the length at the fitting with pins.
I pinned the lower part symmetrically, drew two nice paralel lines and cut off the excess.
I serged the the lower hem, ironed it and sewed on. When you sew a circle you may lock just at one end (over the first line of stitches).