I used Posca paint pens for the 'tape measure' and writing.
This is a fantastic gift in my view - a lovely thank you message, cost effective and, provided you have paint pens, really quick and easy to put together. Older children could put these together by themselves. I applied the paint work for Eli, though he was with me all the way from purchasing the pots and plants (pushing them around in his miniature Bunnings trolley - it must have had a dodgy wheel as it kept pulling to the left!) to putting the flowers in and watering them. Ticks all the boxes for me!
Little Eli took great delight in presenting each of his teachers at church with one of these. I am pleased to say that they were well received!