Open Illustrator, have a new document. Grab your Elipse tool.
Hold shift, make a circle.
Copy the circle. Paste. Make the fill white. It's just being used as a tool.
Before we go any further make sure your pathfinder tool is open. Window > Pathfinder.
Drag your white circle overtop your black one until you make a moon.
Select both circles. On your pathfinder box click the Minus Front button.
Now you can do these all different thicknesses and cluster them together if you want. Consistency doesn't have to be your closest friend.
and Idk about you but these would look real cute clustered together with those stars in the other tutorial. HINT HINT.