This is a wonderful tutorial that teaches you how-to-make your own owl. Visit Pinky Higgs'sblog for step by step detailed, easy to follow instructions that come with images. the pattern instructions and downloadable template here for you all.
I found one Ideogram - online box template maker. Choose the box design or envelope you want, then type in your own dimensions. A PDF template will be generated for you. Download the file and print it out on decorative paper or use it as a die-line for a project.