I only cough if I take too large of a pull. Right now I'm using a 50/50 blend. I am vaping to quit smoking so I'm using 12 to 18mg nicotine but have a tank with 0mg in it for the flavor (because at home I tend to vape a lot and I don't like nicotine sickness). I don't notice a difference between nicotine vs nicotine free pulls, both can make me cough. My suggestion is the same as everyone else's, take smaller pulls.