To begin your project, cut a piece a thread that will be long enough to go from one end of the section you are working on to the other end. Create a quilter's knot by wrapping the thread around the needle twice and pulling it through.
Next, take your fabric and insert the needle through the fabric without pulling the thread through. The proportion of the sashiko stitch is about 3:2, with the longer stitch on the right side of the fabric. Continue running the needle through the fabric without pulling the thread through until you have multiple stitches on the needle.
After you have several stitches on the needle, whatever number you are comfortable with, push the needle through the fabric and pull the thread all the way through. Use the sashiko thimble to push the needle through the fabric.
Pull the fabric taut to ensure there is no puckering. Continue until you have reached the end of the row and tie another quilter's knot, leaving some slack at the end to compensate for any puckering.
If you are doing a pattern with any change in direction or angles, leave a little loop at each point on the wrong side of the fabric, again for puckering.