Gestural drawing, especially in figure drawing, ofen uses circular, flowing marks, perhaps because of the rounded human form. You can, however, use other kinds of marks in gesture drawing. This drawing of a clenched fist uses spiky, scribbly marks to express the contained, angry energy in the fist. Lines converge and create shadows that begin to suggest the form in space.
You can use the side of a piece of chalk or charcoal to create a gesture drawing with a strong feeling of weight and form, pressing more heavily on one side of the chalk to create tonal gradation within the single mark.
Try finding a range of subjects to use in gestural drawing. Try using gesture to describe a hand expressing different emotions. Draw a hunched figure, or someone dancing. Do a gesture still life of a favorite teapot, or an unfriendly cactus.