To make button loops isn't so hard :) Begin with 1" (2,5cm) wide strip cut on the bias. Since I need only two loops on each cuff , I cut short strip. I trim seam allowances to a bit less than tube's width. Turn the tube right side out. Straighten it. Pin and baste loops in place. Before sewing check the loops are identical in shape and lenght.

if you have any questions, please, do not hesitate to ask.