This is indeed a blending process with a textured photo, and the blending mode varied on each photos, according to the tones or the rendering, so there are no rules but one secret I give to you : I always make the subject pop up by erasing the effect on its place...the textured effect will be around the subject but not on it ;-) Well, that's not exactly true because sometimes I blend more than two photos, so in this case, I leave some effect on the subject, but I make it so the subject is still contrasting more than the background by erasing 1/2 effect if I added 2 photos (I don't know if my explanation in english makes sense 😊 )...the skill is to make the whole uniform and not uniform at the same time 😄