Just be careful when researching about vaping voltage and power. There are extreme vapers out there who does sub-ohm coils and vapes at 15 to 100 watts. There is no need to follow them.
I've rebuilt my protank coil head (30ga, 8 wraps, 2.4mm diameter) and it is reading 1.9 ohm. I'm vaping at 3.4 volts / 6 watts. This is abnormally low (my usual vapes are around 8 to 10 watts), but it is giving good vapor and I'm happy. This probably a good example of what the guys above meant by finding your own sweet spot.