I just saw this posted on someone's Pinterest board. Soooo adorable! I'm going to try this with my kids.
Print out a 'Footprints' poem or any loving message on white paper. Take dad's shoe (when he's away to make a print. Use paint that will wash off. Next have your toddler print his little foot on top or next to daddy's shoe print.
Next glue paper on top of a bigger colored paper for a nice border.