Julie asked how I fostered independent play. Frankly, I have no idea. However, I can say that the independent play is 80% centered around transportation. Kiddo is obsessed with organizing his transportation in different ways and recently I have been listening to him making up elaborate stories about the adventures of his cars and trucks and buses.
I made the above "road" for Kiddo's obsession. It's two large pieces of matte board and I can fold it easily and put it away, but usually it is just out in our living room. A small price to pay for a bit of free time. For the record I would like to state that I am not responsible for the excessive accumulation of toy vehicles you see in these photos (this is just the tip of the iceberg).