This tip eliminates the need to measure and pin the hem before sewing it in place. It's especially useful for fabrics that are too delicate for pins. There are plenty of hem gauges available to purchase, but I prefer my home made ones because cardboard stays in place better than metal. A hot iron and cardboard might not sound like the most sensible combination, but if you move quickly the cardboard will be fine.
You can make several templates for different hem widths, or draw several lines on one template. Here, I'm using one that has a line at 6 mm (1/4") for the first fold and total width of 2 cm (5/8") that is used as guide for the second fold.
Working on the wrong side of the fabric, place the long edge along the hem and turn up the first fold.
Press quickly with the iron, pushing the iron up against the cardboard rather than moving it sideways.
First fold done, look how crisp and neat it is.
Line up the second fold with the upper edge and press again. Make sure the fabric is pulled relatively tight against the cardboard, but not tight enough to stretch.
And we're ready to sew with no need for pins. Bliss!