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Sounds like, technically speaking, you know what needs to be improved (WB, etc.)
My advice would be to work on your posture =)
I know that sounds funny, but if you hold your camera properly, you should be able to pull off that shot at 1/10th second without a tripod (my students practiced and pull it off easily all the time now). Also, any reason you were shooting at 1.6 instead of 1.4? If not, drop that to max ƒ-stop. That'll give you 3 1/3 extra stops of light.
You should be able to shoot that same picture at ISO 200 with those changes.
Now it's all just post processing like Ben Egbert suggested =)