My way;
I try to pink the edges when I can. Or a rolled edge on a serger.
Then I use a loose wide zigzag over a clear fishing line.
Quarter my ruffle and pin it on then I use a basting stitch to apply the ruffle.
It is easy to pull up the gathers and adjust using both hands to hold the ruffles in place and stitch.
I anchor the line with empty spools at each end.
Sometimes I insert 50lb test line to the rolled hem edge.