Draw a long, narrow rectangle or tube shape
Add a rounded bulb at the bottom
Connect the bulb to the tube smoothly
Draw a thin vertical line inside the tube
Add a second line beside it to show the glass outline
Draw a smaller inner line from the bulb upward to show the liquid level
Shade or color the liquid area red or blue
Add small horizontal tick marks along one side of the tube
Make some tick marks longer than others
Add a top cap or rounded end if desired
Clean up the outline and erase extra lines