I second the idea of a mosaic type of art. I’m exhausted at seeing “graffiti style” painted murals covering every inch of flat space in our city.
Nikki de St. Phalle has made a lot of public art all over the country, but one especially, in Escondido, CA at Kit Carson Park is called the Iris Sankey Magical Garden Trail is a walled in (the wall is also covered in mosaic) art garden. Here is a wide view to give you some inspiration. And here is a detail and another detail She used handmade ceramics, mirrors, shells and found objects to create her mosaics.
Another thing that I have seen that is very fun to make and pleasant to look at is to invite peole (especially kids) to design a ceramic tile that will then be incorporated into a bigger piece of art. There may or may not be a theme to the kid’s designs, or you could grid off a picture and have the kids paint their section of tile (like you used to do in art class, only with ceramic tiles instead of drawings on a piece of paper). You could pick a famous painting like the Mona Lisa or you could have a kid or another artist create the original drawing or image and then it would be gridded off into 4 X 4 or 8 X8 or 12×12 inch tiles, in which each person’s section would be “replicated” by the kids, then the whole thing would be assembled on a wall or other 3-D object. Here’s an example of that But I’ve seen these types of tiles adhered to walls and all sorts of things, or layed out in courtyards. Here’s a very crude example of the grid method to illustrate the technique here
Here’s another really neat inspiration for a mosaic