Start by making 2 lines, like this.
Then make a square.
Make a line inside the square, like this.
Then, make the other one on the opposite side.
Make 2 overlapping perpendicular lines, like this.
Next, make a circle starting from the top corner of the square.
Make a circle on each corner.
Make another circle surrounding the original one. Be sure to use the parallel lines you created as a point of reference.
Then make three lines between the circles, like this.
Repeat this step on each side.
Then, using the center line, make a line connecting the right circle, like this.
Join the left side with the center line.
Use the right line to follow the curve and join the left side too.
Now repeat these steps on the other 3 sides to finish this pattern.