Installing picture frame moulding or shadow box molding is easier than you might think. I did it myself... and you can too! Here are my step-by-step instructions for this simple wainscotting DIY project. It's is a cheap project with big results.Installing picture frame moulding or shadow box molding is easier than you might think. I did it myself... and you can too! Here are my step-by-step instructions for this simple wainscotting DIY project. It's is a cheap project with big results.