Buy a Lace with a Scallop on the edge that is wide enough to go around you and you can pin your side and back piece together..
Lay your back piece on the fold and pin your pattern piece in front of a Straight simple jacket and make it the length to your ankles and you only have to cut out the top edge of your two pattern pieces together as you have laid them as if they are sewn on the fabric... and the scallop will be down the front
Sew your Shoulders together and just flat roll edge the neck.
at the bottom you will flat roll the hem.
Lay out your sleeves so the scallop in on the edge of your sleeve and sew your sleeve onto the jacket ...DONE...