When finishing up a cake covered in fondant and you've got either powered sugar or corn starch still on the cake...what is the best way to either get if off or make it look like it's gone away?

You can use a clean, dry pastry brush to brush it off.

I don't roll using ps or cs anymore, I use a thin film of shortening on the counter, rolling pin, and my hands. Works much better and the fondant doesn't get too dry or crack the way it can sometimes with ps or cs.

That's so good to know

On Sugarshack's fondant DVD, she suggest that you rub off the cornstarch/PS marks with a very light layer of shortening (rubbed on with a paper towel). Then, go back over it with a dry paper towel. Works like a charm!