Creating a glass painting masterpiece is easier than you think
First, print out the image you want to paint. Make sure to print the image the size you want it to look, because you'll be tracing on the glass as it is. Detach the glass from the photo frame and tape your image to the back of the glass. Once your image is secured, start tracing it on the glass using a black permanent marker. You can use a cotton swab with nail polish remover to clean any mistakes without leaving a trace on the glass.
After tracing, take off the image and turn the glass around. The side of the glass that you didn't draw on should be facing you now. You'll be painting with acrylics on this site. Start by painting the details first, which could include eyes, shadows, highlights, jewellery, etc. You'll want to let it dry for a day or so until it's completely dry. Put the glass against the light to see if the paint looks transparent and you need to add another layer. Once you're satisfied with the details, it's time for the second layer of paint. Paint the larger areas of the design with generous amounts of paint, covering the details you already painted. Let it dry for a day, turn it around, and unveil your masterpiece.