dry burn is a way of "reviving" used atomizer head. this requires taking the head apart and burning the coil intentionally. if you are new to vaping, you don't need to worry about that for now. eVod heads are pretty cheap and just replace them until you feel the need for it.
due to the design, a few small drop of juice onto the contact is normal. there is a clear tubing between coil and contact. if you are getting juice while vaping or hear too much gurgling, that means the coil has too much juice. when you have this flooding condition, you can stand the evod on its drip tip and let the juice slide out. more common (but messy) way is to unscrew the bottom piece and blow from the bottom and let the excess juice blow out of top chamber.
so why does this happen? bad atomizers. Kanger atomizer heads for eVod/ProTanks are known to be hit or miss. the juice is sucked into the coil area by small open in the bottom where the excess wicks are exposed. there are usually a few wicks from the coil and a few additional called flavor wicks. these wicks fill the hole and slowly sucks the juice in as the coil burns them. if these wicks aren't filling the hole completely, extra juice might flow into the coil area and flood it. opposite condition also exist. if these wicks are packed too tight or too much gunk on them, the natural juice flow will be too slow. This results in "dry hit" where you get burn taste instead of juice flavor.
there is nothing worse than the burn taste or hot juice hitting your mouth. when this happens, just change the atomizer head and wash the bad one under warm water and let it dry over night. when cleaning, blow through the chamber. this might do the trick of reusing the head. if it doesn't work, save it. once you learn how to do dry burning, you can "fix" them.
i know this isn't a "do this to prevent a leak" answer, but slowly learning more about the components will definitely enhance the vaping experience and save you money in the long run.