So I took a little break and thought I would show you.
Start by drawing your grid out on your fabric using your preferred marking method.
In this sample I used a 1/2" grid.
Stitch curves and hit the line on the intersections.
And then go back in the opposite direction.
Sometimes you end up in a corner. Just squiggle your way to an intersection.
Then fill the centres with squiggles. You just want to flatten that middle bit, try not to go over the lines you have previously stitched for the curvy grid. Travel from one centre to the next by going through the corners.
And this is the back so you can see what it looks like without the grid marks.
When you get more of them done, the ellipse shapes take on the form of a grid as they puff up.