I realize that Father's Day just passed but I thought I'd share what we did for my husband and you can stow it away for another day. You could use this same idea for birthday's or any other special day. Since we're all packed up for our move we didn't have many supplies to make something really cute or impressive but this may have been even more fun!
First I sat my boys down and had them tell me all the reasons that they love their dad. (Some examples? "He watches Indiana Jones with us", "He plays good music in the car", "He helps us") Then I cut letters out of construction paper to spell out "Happy Father's Day". Once they were cut I wrote one reason on each letter and then had each of the boys help me decorate them. On Father's Day we hung up our sign in the living room for Dad to find.
Super easy. Super fun.