Wicking is a big part of it too. You have to make sure you can get enough juice to the coil. Twisted 28 is a really easy way to enhance flavor and vapor. I usually build my rta tanks at 0.6 or 0.7 with 26g, 5 or 6 wraps for single coils, and my drippers with twisted 28g dual coils that a average out to 0.5