My husband & I like to leave sweet notes or draw funny pictures on our daughters' bathroom mirror so that when they wake up in the morning, they have something that starts their day with a smile. As much as they roll their eyes and act like they don't care, we know they enjoy the notes and get the effort & love put into it. They, too, leave us notes on our mirror (albeit with my $20 MAC lipstick and not the EXPO marker laying right there... omg. )
Moral of the story? The little things we can do for our little ones who grow up so very fast take little effort. These things they will take with them as they grow into adults and have children of their own. So make someone smile today... leave a note on a mirror (dry erase/EXPO markers are safe) or hide it in a backpack or under a pillow, and you'll see how this kind & simple gesture brightens someones day.