Yay for fathers! We've all got one, right? Some of us are married to one, are a sister to one, or at least know one, and making them a card to tell them you're thinking of them is SO simple, and can be fun too! Just take a sharpie to some card stock and go buy some social envelopes, and you're good to go! Mad and Max think its especially cool and wonderful to get to use "pregnant" markers... or sometimes they're called "impossible" markers. For some reason the word "permanent" just doesn't seem to stick.
Clearly perfection is not the key here. Just have fun with it.
Try that super fun herringbone pattern you've been wanting to doodle.
Ignore your mistakes, and maybe he will too? It's just a theory. I'll let you know how it works out. :)