The upper body on uke is REALLY still. instead of starting on hold all, use relax all. Not only does it give more momentium, but it also helps make it look more fluid
Well, the thing about that sort of decap is that most people have done it However, if you want to make it better I would suggest playing a bit with the glutes and lumbar with everything else relaxed. You may be able to get the other arm off as well.