thankful tree with chalk...*Collect them all and put in basket. Have guests randomly pick one and read out loud as if it's their thankful. "I am thankful for...and read the one they picked. Maybe have people reveal who wrote it."
If you have children or work with children/youth, try and keep a constant prayer tree with plenty of blank labels. This will encourage children to pray without being prompted as they know they can go up to it at any one time, write a prayer on it and hand it on a branch. Adults like using them too in worship and if you already have a house plant, you might enjoy using it too.