Bette and some others had worked ahead, crocheting between doilies to make large expanses of lacy coverings, so that all they had to do was wrap the expanses around the tree and close up the back side. On my tree we were more improvisational, simply applying the doilies to the tree with push pins and then crocheting cords between them.
By contrast, the people with the largest tree just made a single big wrap.
There were unexpected obstacles to working in situ: where to put your hands and your thread! When there's a branch in the way you have to be able to adapt your stance. Here's me in action, trying to make my wrists bend in ways my grandmothers never taught me. (thanks to Suzi Z for the last two photos)