This could be a fun project with little ones, go on a thrift store trip for the items or set up a scavenger hunt with nifty items and then the culmination is making their very own planter for the summer.
Just print off any picture you want, then spray paint a piece of wood black, cut the picture to match the size of the wood. Using Mod podge coat the wood then lay the picture on top. Once it has dried thoroughly, use sandpaper to rough up the edges, then put a layer of mod podge over the picture. paint some eye hooks and use pretty ribbon as a hanger and voila!