It’s difficult to tell the difference.
Both practices are rapid movements of the pen, marker or pencil, attempting to capture a form quickly.
A tag though is made to be seen. It’s intent is to pay homage to the creator.
Gesture drawing is an exercise. Their intent is to loosen up the artist, and then hit the wastebasket.
It is only action, the gesture, that you are trying to respond to here, not the details of the structure. You must discover – and feel – that the gesture is dynamic, moving, not static. Gesture has no precise edges, no exact shape, no jelled form. The forms are in the act of changing. Gesture is movement in space.The Natural Way to Draw. Kimon, Nicolaides, pg 15
A reminder: Don’t fret. It’s fine to go through reams of paper:
Feel free to use a great deal of paper and do not ever worry about ‘spoiling’ it – that is one of our reasons for using cheap paper. I notice that students working at their best, thinking only of the gesture and not of making pictures, often throw their drawings into the trash-can without even looking at them. A few should be kept and dated as a record of your progress, but the rest may be tossed aside as carelessly as yesterday’s newspaper. Results are best when they come from the right kind of un-self-conscious effort.The Natural Way to Draw. Kimon, Nicolaides, pg 18