Safety pins can be very helpful for temporarily holding patches or seams in place before basting or regular stitching.
It can be a bit tricky if you primarily sew by hand, as you can easily snag your thread on the pins or prick yourself, but it depends on what you're sewing. In such cases, safety pins are better.
For example, if you're attaching a somewhat large patch, you can first secure it with pins, then baste (sew some long, large stitches) around and/or through the patch, before sewing sashiko stitches or other types.
Approximately 60 pins come in a practical small container, making them easy to carry if you like to travel with some repair supplies.
The pins are 3.8 cm long with a needle head of 0.58 mm