ArtMetal

There are several ways to go about it.
Marilyn suggested a good one for radial symmetry like this and then there is the way I did it.

I started the folds by tracing them with a hammer and stake moving along the bend line making the bend. kind of like if you took a spoon and clamped it in a vice, laid a piece of foil on it, and then pressed down with a finger just to the side of the tip. It would start a fold at that spot.
If you move the piece over the contact point following a line, you will start a bend in that pattern. It is point deformation.

Marilyn suggested bending a piece of steel strap to match the radial curve and sharpening the edges, then pounding the metal down over the edge of the strap with a soft hammer; after which you would move to the next location and repeat til done. Additional folding work would be required but you would get your geometry and a start all in one go.

G.

Gene Olson, Sculptor
Elk River, MN