My kids love these plates. Their favorite thing to do with them is write how many days until their birthday. Sometimes the number on it is over 100. :)
It is easy. Not kidding. I buy my plates at Hobby Lobby. I think they are between $2.00 and $4.00. I string ribbon through. Then I write on it, with Dry Erase markers. That's it.
I have only found about 3 plates that the Dry Erase Markers don't work on, one from Cost Plus and 2 from Target. Just test the marker on the back of the plate. If you really love it but you can't erase the marker, paint it with a spray paint, clear lacquer. You should be fine writing on it.