I just switched from a single coil, but that one was only wicked to right above the glass, nothing was showing in the tank at all. It was a thinner Scottish roll, I didn't want to over stuff the cotton. It worked pretty well, mostly because I use the Limitless Plus while I am walking to and from work, and how I hold my mod as I walk let the juice soak the cotton between hits.
I switched to dual coils last night, I just went with cut strips off of a cotton pad about 6-7 mm wide, tore off the top and bottom layers and those sit right at the top of the glass or a little higher. I will find out how well it works here in a few minutes when I leave for work. Well, that isn't true, I ripped though almost an entire tank last night, no dry hits. But I made sure to tilt the tank back and forth a few times to make sure the juice was hitting the wicks.
I don't like the wicks hanging down too far, just personal preference.