A Paderno pot lid defined the inner edges of my circle.
Then it was down to this wide-mouth Corelle teacup to make scallops on the large circle. Note I have used masking tape on the cup to mark the placement on the line.
After all these maneuvers, I was left with this outline on tissue paper. Does it look like anything to you yet? :)
To make my pattern symmetrical, I folded the tissue in half to mark the centre and darkened the lines on one half with a black Sharpie.
I folded freezer paper in half and lined up the creases on the two papers. Then I traced the line.
Folding my freezer paper in half, I cut along the black line, then folded it in quarters to trim my scallops to a uniform shape. I was left with this "tree" shaped background, upon which I will applique leaves and a trunk.