Recently, I have been thinking a lot about using only 1 X 2 Lego plates to build models. 1 by 2 plate is the smallest unit that has a connection in Lego system. They should be able to build a as complex (or simple) structure as you can imagine. One simple model I built that is enough to impress my children is a dog model. Since 1x2 plates are easily available at home or to buy from Lego stores, I do encourage you to try it.