Does it gurgle? Excess fluid spits out the atomizer towards the mouth, and all inside it, and will eventually some will come out the other end. It's designed so leakage goes on top of the battery rather than into your lap and on your shirt. Several techniques help. Always clean off the coil chimney when refilling, the air tube if necessary (or absorb run-off out the mouthpiece) to avoid endless buildup. Avoid short hard puffs which pull in fluid and then doesn't use it. Nip flooding in the bud, if you notice it, turn it upside down enough that the wick is above the fluid level and run it enough to use up some excess. Watch out for heat or bringing it in from the cold, the
juice expands. It may help to sit it tip down in that case also, and generally clearos like to be sat on their side, rather than standing tip-up like a dripper.
The coil can also loosen if not screwed in good.