Stabilizing Circumference Stitch: To be extra sure that the hole doesn't expand or fray, place a running stitch around the circumference of the hole before beginning. Place the stitch about 1/4 inch (~6 mm) away from the damage and ensure the vertical and horizontal darning stitches extend past it.

Gap Between Rows: Try to create a gap between each horizontal and vertical row that's the same as the width of the yarn. This will create the most balanced weave structure, with the horizontal and vertical yarns appearing an equal amount like a checkerboard.

Too Close: The yarns are packed too tightly. This will make it difficult to weave in the vertical yarns and the resulting woven patch will be thick and unbalanced.

Too Far: The weave structure will be very loose with visible gaps.