I'm liking a simple 26 awg SS316L wrapped 4 times around 3 mm ID across the board for the Wasp Nano, the Gorge, the Trinity RDA(U.S.1 version 2). That gives me a μE 0.30 Ω, which does suitably well for me. I run a single cell 18650 mech, or an Eleaf pico squeeze.