All my builds on RDA's are lovely and cool, 6mg juices taste hot when i vape them, but 3mg is a super cool vape.
So is it your actual RDA getting hot? or just the vapour itself tasting too hot?
Vapour! I use .4mm Kanthal normally in dual coil and aim for around 0.6 - 1ohm. So 6/7wraps around either 2.5mm or 3mm piece.
Thats off the top of my head I haven't tried building one in ages!