A pick stitch in sewing is a simple running stitch that catches only a few threads of the fabric, showing very little of the thread on the right side (outer side) of the garment. It is also sometimes known as 'stab stitch'.
A pick stitch can be made from either the inside of the garment, or the outside, depending upon how much thread is meant to show on the outside of the garment. A pick stitch is commonly used for making hems, although it is also used with contrasting thread to create a decorative finish on some garments. It has decorative uses in embroidery. It is exceedingly useful for inserting zips and is surprisingly strong for this purpose. Many home-sewers and new dressmakers find this much easier than inserting zips by sewing machine.
A finely made pick stitch is difficult to accomplish, and can be achieved only with practice. As long as a sewer or dressmaker is patient, it works very well and is not as difficult as it sometimes looks! A pick stitch along the outside of a lapel is a hallmark of a "high-end, hand-made" men's suit or blazer.