Have you tried Mod Podge Mega Glitter?
If not, you'll be amazed by the shine! I've been trying it out on lots of different surfaces and on top of other paints and love the results.
It is available in 3 different colours. Hologram, Silver and Gold.
I painted it onto these suede effect shoes.
Silver, hologram and gold straight on to glass
Hologram onto Folk Art Garnet Metallic multi surface acrylic paint
Gold on to Folk Art Pale Yellow multi surface acrylic paint
Silver highlights in marbling paint background
On top of Mod Podge Sheer paint (aqua plus silver, pink plus gold,and purple plus hologram)
Silver Mega Glitter on glass
Check out my YouTube video here