I would find it helpful in critiquing your design if you could give us the overall dimensions you're
designing for or the space restrictions you're designing to. I agree with David (father down the string) that the top section height should be proportionally increased to that of the bottom.
I have an antique corner cupboard that I think has pretty good proportions, although it may be that I'm just used to it. The upper doors each have eight glass panes, the bottoms single panels and there is no drawer. The overall height is 87 1/2". There is a piece of trim 2" wide at the waist, from 33 1/2" to 35 1/2" from the floor, and from the trim to the cornice top is 52". I can send a photo if you'd like. If I was re-designing it and wanted to add a drawer I think I'd make it about 4" deep and put the bottom of the rail or drawer blade at the 33 1/2' above the floor where the waist trim starts now.
As regards an earlier question you asked about the joint used between the flat front stile and the 45 degree board attached to it, mine and many others I've seen are face nailed into the shelf edges and filled and there's no visible sign of any additional glue blocks or additional support. It appears that the two boards are cut and planed to mate tightly together and there's probably glue between them. Also, the vertical front pieces of the cupboard are 3 1/2" wide and the door stiles 3".
I hope this helps. I'm sure you'll do a great job on this just like you always do.
Joe Grittani in cold and snowy Dayton, Ohio