For me, this kind of artwork begins with paper and pencil. And well, my hand drawn style always ends up ready for the pages of a children's book. =)
After pencil, I retrace the designs in fine point marker, scan them into my computer, then use Illustrator to create vector outlines. I also use the program to color and shade the designs. Or another style I use is to just scan the smudgy pencil to create a texture, like I did for the green striped wallpaper background.
Once the Illustrator elements were put together, I pulled them into Photoshop. Photoshop allowed me to easily create colored textures for the frames, pull in photo images of fabrics for portrait backgrounds, and to add my picture as the final portrait.
At this point, now that all the artwork and images were together, I could print as many as I wanted! I used Costco's photo holiday card printing service. But I couldn't just leave it without a little texture, and as was the plan all along (remembering those tree stickers!) I added googly eyes to the owl (luckily they were stickers too), a balsa wood bird, and the fir tree sticker to my hand - which looked odd in my photo shoot to be holding an imaginary object.
Can I also say, suspenders are not as comfortable as I thought they would be =)