How can I make pattern on an hourglass surface?

Hello all,

I am attempting to make a pattern on this surface of my attached model resembling the below:

The only thing I can think of is sketching on a plane normal to any part of that surface and make sketches and the extrude with offset from surface.

But I don't know if using that method will make the necessary cuts right here:

Any ideas?

SolidworksParts And Features