Marcus Juniel in Southern California does some pretty big bends on junipers. He says that the best time to bend in when the tree is dormant (usually between Halloween & Easter) when there isn't much sap flowing. Let the tree dry out before bending because if it's too hydrated it will snap like a piece of celery. Also wire and wrap the tree to protect it from snapping when you bend. In the pics he uses a wire spine along the outside of the bend with jute wrapped tightly around the tree to minimize breaking.
At his demos he says if he can bend a tree this big, you should be able to bend smaller branches with great success. By the way, the tree in these pics is alive and well, I saw it last week.