i'm doing a cake using white fondant to cover the cake, i then want to give the white fondant a green pearl finish so i ordered the luster powder but i've never used it. instructions please?

I have a special brush I use for luster dust. It's actually one of those make-up brushes you use for applying blush. They're soft, large and - most important - inexpensive, so I buy them and use them for applying luster dust ONLY(!). It requires a bit of patience to apply luster dust to a whole cake, because you need to apply it a little bit at a time. You can't put a whole lot in one place and hope it will spread out. So easy does it, but other than that, there's no special trick to it. If you're worried about it, I'd suggest you roll out a piece of leftover fondant and practice applying the dust to that. Good luck and have fun with it!