CLOSE TEAR: In most cases, stitch the tear closed before attaching the patch. This will seal the tear on the inside so it doesn't grow bigger or get caught while the garment is being worn. See Whip Stitch on a Tear.

UNDERPATCH: If the tear is too large to be stitched closed, use an underpatch: a smaller patch that's sewn over the hole on the inside before the main patch is sewn on the front.

PATCH INTO A SEAM: For a patch that goes into a garment seam, use the same measurement steps but leave the seam allowance along that edge unfolded. The seam allowance will instead be sewn into the garment seam.