After painting them a matte gold acrylic by Holbein and letting the paint dry, I applied the adhesive size. This is a special glue made for metal leaf and foils. It goes on white and when it becomes clear, it is tacky and ready for the foil application. I prefer Wunda Size as it is water soluble.
My apologies that this is so hard to photograph In person it looks great.
I get my holographic foils at Royal Design Studio. They have a great range of holographic and regular foils plus you can order it by the foot, yard or roll.