Kanger coils are so small that having a little too much cotton has never been an issue for me. After installing the coil, take a bit of tightly twisted cotton and thread the coil. The wick should be just snug inside the coil. Clip the excess and fluff with a toothpick or something small so the cotton fills the gaps. I've never had flooding or dry hit issues wicking this way. It does take some practice to get just the right amount of cotton though.