However, this can be a bit too fancy sometimes and you might be wanting something a bit plainer with a bit more dignity. The answer is the straight edged hem.
This is a very easy hem to make.
Step 1: Beginning
With 3mm needles I cast on 36 stitches in gold yarn and knitted 7 rows in stockinette stitch. (One row plain and one row purl, starting with a plain row.)
Step 2: The turn line
After knitting this row, the next row is also a knitted row.
This completes the turn section of the edge.
To continue, I have knitted 7 rows in stockinette stitch starting with a knit row.
Step 3: Continuing on
The piece that is knitted in "gold" will be your jacket (or sleeve) edge. As you can see in the photo, the old hemline (your cast on edge) desperately wants to curl up!
Your new hemline (where you see the raised knitted row) will not turn up once it is sewn neatly into place on the wrong side.