This photo was taken at a parade in Waingapu, Sumba. It’s a wonderful photograph that depicts how the women “step into” and wear a tubular sarong.
The two women on the left are wearing sarongs with supplementary-weft panels affixed, along with ikat designs. Notice, too, the tortoise-shell hair combs they are wearing. The tubular sarongs are held up either rolling down a bit of the upper portion of the sarong and knotting it in place (shown here). A second method is to literally pull the sarong tight against one side of the body while the “slack” portion of the opposite side is held firmly against the body with the upper arm and, thereby, preventing it from falling down.