For the samples, I used decofoil from iCreate (ThermoWeb) and Ranger's foil sheets, both of which I found at Hobby Lobby.
I used some images that are in Cricut Design Space and cut them from pieces of Cricut vinyl left from previous projects. In some cases, I mirrored the image before cutting, so the word would be right side up when the foiling was completed. The following photo shows the vinyl image, after cutting and weeding. What would normally be the right side of the vinyl is facing up, and the adhesive side of the vinyl, which will end up being the right side of the project, is down.
I carefully lifted up the image from the backing sheet, and placed it on a non-stick craft sheet, with the sticky adhesive side up. Then I laid the foil on top of the vinyl piece, with the right (shiny) side of the foil facing up and the backside (usually dull silver or grey) against the sticky side of the vinyl.
The photo below shows the back side of the foil....I know it's a pretty silver color, but it really is the back side, LOL!
Turn the piece over so the right side of the foil is facing up and rub the foil with your finger to adhere it firmly to the sticky side of the vinyl.
Peel the vinyl from the back of the foil and you have your embellishment. Here are a few examples:
You can adhere the pieces to your project with liquid glue, micro glue dots, or Glossy Accents. Here's a page with some of the foil pieces made this way: