Draw curved lines in every other vertical column.
Turn paper other way to make lines contouring in opposing direction. Make sure they match up with opposing lines, touching ends.
Leave the corner open for stars.
Dra a bent contour guideline to draw stars on the open space of flag.
Color with the contour.
Color softly with red crayon.
Bend your coloring with the bend of the line.
Add shadows by pressing harder close to the bertical lines with the red crayon.
Use the blue crayon lightly along the white stripe's vertical line to show shadow.
-alternative color using grey or black.