I really like this cardigan from Anthropologie. It's so whimsical.
It's called the Bell Song cardigan. I actually saw it in the store and -- alas -- it is too itchy for me. I think I may try to recreate it as a sweater. What you can't really tell from the picture is that it has empire seaming. Also there is some runching around the buttonholes -- they don't line up exactly with the buttons. I don't know that I could really recreate that aspect without it just looking like I was inept.
So I would probably concentrate on 3/4-length bell sleeves and the shaping. Without the odd buttons I think it would be quite elegant. And with the odd buttons it's super cute. So you really can't lose there.