Now that school is back in I'm sure you have some lunch bags around the house so why not make a easy card.
You can make these any size you want my favorite size is 5x5. You can make the 5x5 size just by folding up the bottom and trimming the top off so that it is 5 inches tall. The rest is just embellishing and adhering the folded end to the bag.
Here are a few paper bag cards for inspiration.