Usually when I start jerking off, or just greeting my morning wood in the mornings, I always enjoy rediscovering the sensitivity of the glans while pulling back my foreskin all the way while the head is still dry…so the first strokes are really about the friction of the foreskin and the dry cockhead, but then tend to start leaking precum quicky, and the slides become longer and stronger and about stimulating the whole shaft as the head gets moist and less sensitive.