What you're looking for is called a narrow hem and there are various ways of doing this. How to sew a narrow hem. In theory, the rolled hem foot is great. However, the reality is that it is not easy to master. I've been sewing a long time and have limited success with my rolled hem foot.

I would just fold once and iron it flat, then fold it again and iron again. Use a presser cloth between the iron and the fabric to protect the fabric. Pin the hem down and sew the hem. Line up the inside folded edge (not the outside edge) of the hem with the inside edge of the "H" shaped presser foot on the machine. This will keep the needle the correct distance from the edge of the hem. Go slowly and be patient.

Polyester will not take a crease well from ironing. And you need to use a presser cloth to protect the iron more than anything else, as polyester will leave a residue on the iron. You will definitely need to use pins, as the crease from the iron will not be enough. I personally will not work with polyester any more and have not for years, and so perhaps they have made some improvements. However, if it is 100% polyester, it will be difficult.

A rolled hem foot may make a hem even narrower than that. It's lots of fun, *once you get a feel for feeding the fabric in.* Some people find it easier to turn the machine 90 degrees (head/handwheel away from you) and feed the material through right to left.

When I worked at a bridal store, we weren't provided with rolled hem feet. I found the easiest for me to mark the hem, but don't cut it yet. With the right side up, turn the hem under 1/8th inch beyond the finished length and stitch close to the edge. This was especially helpful if the dress was very flared, as it helped tame the edge and the feed dogs eased the extra fabric in.

Then I cut away the excess, close to the stitching, and stitched the second time, turning the fabric the second time.