Put your pen on a piece of paper, and try to draw something with just one line, without lifting your pen.
It’s a fun puzzle to figure out where to move your pen next, and where to leave a line out maybe.
Gestalt: leave out part of the outline and the eye will complete the drawing.
Form loops where lines cross. Let an outline of one thing go over into the outline of another.
Use a shadow edge to move the pen to a certain place. Draw two objects so you can switch from the one to the other.
Also, these are fun to do, and suitable for tattoos, or to draw large on a sheet of paper to frame. They are also popular on some social media where big communities form around this style of drawing. These drawings can look very distinct, or calm, and be suitable as illustrations to go with poems.
Did I mention they were fun? Get drawing!