Update 9/2019 - Filament snaps into the clip with greater holding power.
Wedge the first loop into the lower slot. Use a finger on each side of the clip to snap the end into the upper channel leaving about 5cm of slack. Pinch the filament behind the clip and push towards the loose end. Things should be nice and secure.
0 top/bottom layers
.4 wall thickness
It's best to break in new clips with a scrap piece of filament. A tool might help to snap them on for the first time.