Press CTRL + J to create a duplicate of the selection into new layer but it will also contain the content of the selection. So really depends whether you want underlying content as well with selection or not.I got some problems getting elliptical marquee tool of the same shape and size.
How do I duplicate it?
I like IamSam's approach as you can select the created Path (via the ellipse tool (or any tool as far as that goes) and duplicate it exactly just by dragging and subsequently make individual copies again or select more paths and duplicate larger sets of paths. Each path can be selected individually or in groups for editing as well. Very flexible and powerful. Thanks for sharing.This might depend on what your trying to do. It would help if you explain exactly what you're trying to accomplish.
If you're only trying to make round or oval shapes that can be repeated, you need to be using the Ellipse Tool set to path. Then you have the options of moving, editing, and dragging out a new duplicate path the same size and shape (shift + opt/alt + cmd/contrl + drag). Once you have the shape paths set, then right click and choose make a selection, set the feathering, hit OK or enter.
You can also recreate the exact same shape on a new layer by choosing the Ellipse Tool, clicking on the canvas and entering the shapes pixel dimensions. Then converting it to a selection.
This video illustrates a part of what I explained....But, when you make the second selection, do NOT release the mouse click. While the mouse click is held down, press the SPACE key and superimpose second selection over the first one to see if it is exact. If it is not, release space key while holding the mouse click, use Shift or Alt in conjunction to the mouse click that is still held down, and keep making changes to second selection until it is exact. When you get there, press the Space key and move this exact elliptical marquee selection replica to wherever you want on the image, release space key first and then release the mouse click.