Last year for hubby's birthday, he was working nights and would be getting home at 4:30 AM. I took a bunch of scraps of paper (you could cut a bunch of hearts, and do this for valentines or any holiday, really). We each took turns writing what we love about daddy, "I love you because you play video games with me, give me the day off on Sundays by making us dinner, even if it is leftovers, make my coffee every morning, help with laundry, clean the bathrooms, etc."
The kids had "...help me get dressed, read to me, play wrestling with me, etc". They can come up with all kinds of stuff even at a young age. Then I took each one taped it in respective places, coffee pot one by coffee pot, laundry one by laundry, etc.
So when he came in he saw the first one. Then he said he got all excited when he opened the laundry room door. When he went to make my coffee, there was another, and he realized they were all over the house. So he started doing this fun little hunt by himself. He was thrilled.
We then took them all, had the kids glue them onto construction paper, made a little book for him, & signed their names. It also, helped me appreciate just how much he does for me and our family; even the little things, like taking the trash to the dump.