Easy & simple to do
When crafting you're likely to use shapes to decorate your card. You can create your very own shape template and use it as often as you want.
To create a shape template, just use normal white paper or grid paper. This way you won't waste any precious colored paper during the sketch phase of your template.
When you're satisfied about your sketch, use a scissors or craft knife to cut out the shape. You can try multiple shapes and see which one you like best.
At this point you can decide if you want to use a paper template or maybe a cardboard one, which is a little firmer and easier to trace with a pencil. If you do want to use a cardboard template: put the paper template onto the cardboard, trace it with a pencil and cut it out carefully.