Assess the denim
Check whether the cloth is rigid, lightweight, worn, stretchy or layered at a seam. A soft worn area may need a patch, while a firm panel may support direct stitching.
Flex the garment where it will be worn. The repair must follow that movement rather than being planned only on a flat table.
Support weak areas
A hole is often smaller than the region that has lost strength. Extend the patch beyond the thinning and secure it to stable denim before adding the visible pattern.
Keep pockets, hems and belt loops functional. Stitching through an opening can make the item harder to use even when the patch itself is strong.
Test contrast and care
Place several thread shades on the washed denim. White is clear, while muted blue, grey or natural colours can make a quieter repair that changes gently with wear.
Wash a sample with the intended care routine. The best repair is one whose thread, patch and denim can live together through normal use.