Start with a ruffle
. This one has built in eyelets. You could make it longer than the one in the video if you want and I'm sure you could find more ruffle videos. After decreasing from the ruffle you would, in effect, work a picot hem
but the decrease row of the ruffle would get stitched to the main sock cuff. You would just continue your sock top as you need to for the pattern. Are the sock tops split and laced up or is the lacing more of a trim? If they're to be worked in the round the flat knitting instructions would have to be converted to working in the round but that shouldn't be hard. I'm eager to know how you finally work this out.