When starting off with a new carto, make sure the batting is nice and wet and let it sit for several minutes before using them. That way, the batting closest to the coil is wet enough that it will vaporize your
juice instead of scorching the batting material.
After approximately 10 draws from the carto, squonk your bottle gently while drawing on the carto without hitting the power button. You should feel some resistance and hear a gurgle when juice is being drawn up into the carto and resoaking the batting material.
Keeping them wet keeps them from burning. You can monkey up the draw and make it too stiff if you over-do it, so you'll have to find a balance by experimenting a bit.
I hope that helps.