Pleater,

I do the same pulling up of the pleats at the waist. But I do it for a different reason. I call it "Pre-curling".

Because my fabrics have a tendency to curl outward I have spent a lot of time finding ways to prevent curling.
One thing I found that improves the look of the aprons is to pull up on the "in-pleats" slightly. This builds in a slight amount of roll to the apron edges.
Now when worn the aprons roll gently around the legs and don't curl outward.