Eyelets are worked at the same time as the mitt. The top of the mitt is bound-off using an i-cord bind off, and the i-cord is woven back through the eyelets. Wear these as slouchy as your heart desires!

~Row 12 of the Thumb Gusset section should read:

Purl to Thumb m, m1L, k9, m1R, knit to end.

Thanks so much to Ravelr chikako!