So, here's how to bling up your edible decorations with luster dust.
Luster dusts are made using minerals such as titanium dioxide and mica. They are usually labelled "non-toxic", which actually isn't the same as edible! But the small amount consumed is generally nothing to be concerned about.
Luster dust can't be mixed into fondant or tylose paste the way that powdered colour can; the lustre can only be applied to the surface - the bling doesn't survive the kneading process.
You can use the dust dry, or add a clear alcohol to it and paint it on as a liquid. I'm talking about using it dry here.
(Using tylose paste)
Roll out the paste
Sponge on some luster dust
Use the sponge to "polish" on the dust
Cut out shapes
Luster dust comes in various colours. If you are applying a white or pearl dust onto coloured paste, it will make the colour look paler.
And if you want an intense luster - for example gold or silver, then it is a good idea to make your paste a corresponding colour first (yellow for gold; grey for silver) before dusting.
If you re-knead the paste, the luster is lost, but the pigment remains, so you will have to re-luster after kneading.