We've done this in February for the past few years and the boys always love it.
I write on the chalkboard " I love _____ because. .." and everyone writes ( or tells us what to write) a reason they love that person.
We said it had to be something nice. Of course, rowan to Eli says something about him being crazy, eating pizza, and falling asleep. I let it stay since Eli thought it was the best thing ever.
They usually stay up for about a week each so I haven't got around to putting up ones for mike and I yet.