This is a neat one – a bouquet of lovely flower pens to give as a gift for your grads perhaps. The tutorial actually covers how to make your own air dry polymer clay but I’d be using my oven bake clay to do this. If you have pens that survive baking temperatures their caps are usually fine as well.
For this tutorial I would do as Nash does and use green floral tape on the base. If you cover the pen base with clay the decorated cap may no longer fit and that would be a bother!