This video from Nokia Russia shows how you can use daily objects to make a stand for the Nokia Lumia 920. However, I think you can use these methods for any smartphones. Check out the video.
In the video, he uses 3 methods to make the stand: a sunglasses, a credit card and a couple of clips. I think they are quite easy to make. Here is the video.
Actually, in 2010, I made one myself. Not my original idea but I copied from some video. Here is a picture of it.
Not too bad, isn’t it?