You want to make sure your hands are very clean, free of oils. Your cotton needs to be rolled, one end to a point. If it is too pointy, cut off some of the point. Any cotton should do. Once you have it started, if it still wont go through, you are using too much! If the coils choke it, it will not wick properly. You want it to touch the coil, but not be squeezed. The smaller the hole in the coil, the harder this is to do. I found that getting just the right amount of cotton can be a bit tricky, especially in tanks. If you buy cotton that is in a pad, it might be easier to judge as you will consistently cut a certain sized piece.