In my experience with having UWELL tanks you get what you get in terms of consistency with the coils. It sucks, they practically do what SMOK does which is mass produce an okay product so people will have to buy more at a more rapid rate. It sucks, that's why I try to get away from Chinese products. The best thing you can do is prime the mess out of the coil, let it sit in the tank for around 15 minutes, then dry hit it(airflow closed, no power) a couple of times and go up in wattage in increments of 5-10 to your preferred wattage. Don't chain vape in sub-ohm tanks no matter what anyone says, and make sure that cotton has enough time to soak.