2. Mark auxiliary lines and node positions.
3. A curve is completed.
4. Hold down the Shift key and copy the past in parallel. Then Ctrl+D makes an infinite copy.
5. Select and weld them.
6. Continue to copy infinitely with the method of Ctrl+D just now. You will get many curves.
7. Because you want a cross curve, adjust the angle to make it rotate.
8. Copy one, rotate it, and then make them overlap. The overlapping part is the "curve cross shadow" you want. Draw a rectangle according to the page size you want and cut them into rectangles.
9. Change the color you want. OK ~
Hope to adopt! You can trust me privately if you don't understand anything.