It’s very easy, I protected a piece of foam panel with dark paper I calculated and pierced (with a pen tip) 24 gaps in the card panel.
I put two small candies in each balloon. Another option would be to slip a piece of paper with a message … but my kids prefer candy.
After inflating the balloons, you must pass the nodes through the holes made in the foam board.
I stuck a rope to the back because I want to hang it, but you can also place it on a cabinet. The last thing to do is, obviously, to write the dates on the balloons, I just used a permanent marker.
***DIY source and photo credit: www.ohohblog.com