Make sure the coil diameter is less than or equal to the size if the wicking holes, and directly above them. Make sure the amount of cotton you roll up is even smaller in diameter, you want to see a little gap between the cotton and the side of the wick holes. Make sure to leave the other end of the cotton fluffy. For mine, I pull the rolled side of the cotton down thru and leave the fluffy side at the top of the coil, and then cut my cotton about halfway down into the tank. Take a few hits, tip it over and watch it bubble a few times, rinse and repeat. Hope that helps.