Pin-Tucks By Hand

1. Use extra-fine thread the same color as your fabric and a small (#10 - #12) sharp needle
2. Mark the line with a fine-tip washable fabric marker. Tha line can curve if you want it to.
3. Starting 1/4" from the start of the line, stitch a long running stitch back to the start. (The thread is shown as black for clarity; in reality, it will be white or the same color as your fabric)

4. Make a tiny backstitch at the start of the line to anchor the thread

5. Finger-press the fabric right-side out so that the marked line is on the crease. As you stitch a curved line, you may need to adjust the crease to follow the line.
6. Using the width of the marked line as a guide, make tiny whip stitches along the line.

7. Adjust the tension of the stitching so that the marked line is held in a pin-tuck, but not so tightly that it puckers.
8. When you've stitched up to the tail of the thread, clip the tail at the surface of the fabric. The tail is now secured inside the tuck in the back.
9. When you reach the end of the line, secure with a tiny back-stitch and stick the needle into the endpoint to bring the thread to the back of the fabric. Weave the thread, on the reverse side of the fabric, under the stitching, without nicking the fabric. The tail should be completely inside the tuck. Clip.