Leggings need to be really comfy and very stretchy both at the hem and waistline. They are cut to fit and as they are being pulled over the waist, those coverstitches may need to stretch 25% or more. Here is an example of settings for cotton lycra with regular polyester overlocking thread on cones. I sew the hem with the leg turned inside out and stretching gently while sewing, to work as much thread as possible into every cm/inch.

SETTINGS for the Babylock CoverStitch:

Stitch length 2.5

Differential 1

Needle 1 tension 2.5

Needle 3 tension 4

Looper tension 1.5

I have pressed the hem so it is easy to guide the edge along the 2,5cm mark on the piece of tape on the bed of the machine.

The waistband especially needs to be extra stretchy. The stitches are really close together but still neatly interlocking. Please notice how setting the tension for needle 1 on 2.5 is necessary when there is only one layer. If I would use a higher tension here, this would result in tunneling.

I tend to snip knit fabric to mark pattern details. Recently I started snipping the hem and waist folding line while my pattern is still on the fabric. This means that I am assembling and overlocking the snip so that no threads need to be severed. Not that I ever lost a seam!! It goes like this:

I just serge over the snips and then fold the side seam towards the back of the garment and the seam of the hem in the opposite direction.