I can do either or. I use PSE 12... I do have the photo bin. However, I also have the speed scraps(?) scripts for copy/close, which will place all the elements that are open in my current document, retaining file names. Typically I start with what I know I'll use, do a bunch at one time, then later during that same layout it becomes one at a time.
Other times, if I'm using a template I want to stick to closely, I will go one at a time, because I like to bring the elements in to the layout at the right layer position, and sort of start bottom, up, but not have to move them forward or backward/up or down in the layer order.
Really depends on which I think will be faster at the time.