Spanking is an art the big deal is to make it string not hurt or harm. 10 stinging spanks can equal the damage of 1 hard hit. Remember she will be squirming as you see pink coming onto her ass same level of spank will cause the pink to turn red soon enough, after that it can and will go to black and blue but mostly after wards which means it is too late to stop that.

Spanking with one hand does not mean that you can't use the other to excite her actually I highly recommend it.

Spank the fleshy parts of the body the most, cheeks, back of thighs even the back of the calves. stay away from the spine and the ribs. Remember that a spanking is poor punishment because the sub will begin to misbehave to get her bottom spanked