I have recently made some new glass painted toppers for use in my card-making/crafting. The following designs below have been taken from using templates however, the heart design I have designed the swirls in the centre for interest and to be able to use various shades of 1 colour mixed with white opaque (126).
Here I made a Butterfly taken from the template in a craft magazine called Cardmaking & Papercraft. The heart was taken from another template but, then I added in swirls to add various shades like I said before and mainly to give interest too. The flower was taken from another template and again with this and the butterfly used various shades of the one colour when mixed with white and not mixed with white to get darker tones. Below, are close ups of each one:
The Butterfly topper I have left areas blank as my plan to allow patterned paper to be seen through those areas creating another dimension and interest too.
You could however, be more inventive with your artistic talents and actually use acrylic paints with mediums to create something quite similar and still make a topper in the way. This is just an idea to explain that you can use any mediums or methods in your crafting and, allowing you to realise that you can go out of your craft box and bring in the use of art materials within your crafting.