I had a lot of trouble with vivi novas too when I first started, here's what I've learned and it's a great experience now!
1 - When you put in a new head, you have to dry burn to get the chemical primer/grease burned off the head with no juice in the tank. I usually do 16, 4 second blasts and that takes care of that. You can smell the chemical primer burning off and at about 12 blasts it starts to dissipate.
2 - You have to swish it around a bit, sometimes just hold it upside down for a second or two - as long as you don't making jerking motions, it shouldn't leak.
3 - MOST IMPORTANTLY, I found that the dry hits are really really reduced (removed entirely for me) if you cut your wicks down shorter - I bring mine down to about two centimeters on each side of the coil. This produces a warmer vape and no dry hits what so ever.
4 - When it starts to taste burnt again (usually a day or two of vaping) take it apart, rinse everything out, pat the wicks dry and dry burn again until you see a nice red glow of each individual coil - again you'll smell the burnt/built up juice residue burning off as the coils become red again.
Following these steps, I usually have a vivi head last about a month - I almost gave up on vivi novas but the taste of cartos is just yucky to me so I kept with it and it works great now. I use a ZMAX at 3.2 ohms with a 1.8 head.
Hope this helps, Super