In my experience, flooding or leaking or getting juice in your mouth is due to:
These pertain to Bottom Coil Clearomizers:
1) drawing too hard. Long and slow works best. Let the atomizer do the work for you. If you draw hard, especially out of frustration, you will most definitely pull too much liquid through your chimney and flood your tank.
2) during this season, leaving your device in the car in the summer heat: don't do it. Heat will make the viscosity of your juice very watery and it WILL leak and flood.
3) letting your tank get too low. Whenever you fill up a bottom coil clearomizer, you create pressure in the tank. As you use it throughout the day, and that liquid level drops, the pressure inside the tank changes. If you let it get too low, it can leak, gurgle, or spit liquid back into your mouth. To prevent this from happening, try to keep your tank as full as possible. When you're at the half-way point, fill it back up again.
4) over-tightening. Do not over-tighten the base to your clearomizer, and do not crank it down super-hard onto your battery. Most people think that by cranking things on super-tight, it will keep things from leaking. That is the last thing you want to do. Over-tightening can rip apart vital o-rings and negatively affect the pressure inside tanks. Finger-tight is all anything needs to be.
Top-Coil Clearos:
Iclear Series and Vision-style ViVi Novas, CE4/5's, or any "top feeders" where the atomizer coil is at the top and large wicks hang down into the e-juice: Just do your best to keep the tank as full as possible to prevent having to tilt and swirl.
