Draw a simple rounded rectangle or oval for the milk carton or glass
Add the top shape for the carton or the rim for the glass
Sketch the front face and side face if drawing a carton
Draw a curved liquid line near the top if the milk is visible in a glass
Add a small pouring stream if drawing milk being poured
Outline the shape with smooth, clean lines
Erase any unnecessary guide lines
Add a label or simple details if desired
Shade lightly to show form and depth
Keep the drawing clean and minimal