Several years ago, I found some pattern blocks at a discount store for around $1. Being a math teacher (at least back then), I was amazed since I knew how expensive they could be. I bought a set for my nephew and one for myself. I recently have been seeing some various sets for toddlers, so I decided to pull mine out and find some of the templates on line. I did a google search and discovered many. I think my favorite place was PreKinders. They have many animals and flower designs. Then I showed them to Steve and left them for him to do with Hazel while I was at work.
There are many lessons using pattern blocks on line. Since we have decided to go with a Waldorf education, we are not pushing the academic learning but more discovery and creativity at this age so my idea is for her. However there are so many sites you can check out including this one that you can play on-line with pattern blocks. Or Math Playground that also lets you play with them on line without the grid. You can also print your own from sites like this one (by page) or at Utah Education Network you can get them on one sheet (they also have some great activities for all age children).
Confessions of a Homeschooler also has some great pattern activities. Making Learning Fun has pattern templates of letters and numbers as well as Valentines. There are so many things you can do with these. Plus they can just be used to make designs and be very open ended.