If you want glossy, try just creating a layer above the photo and apply black/white gradients to that layer... then set the blending mode to something different. Try lots of things to see what makes the best effect... soft light, screen, etc. Play with the "fill" for the layer also as this will change the amount of the effect.
Plastic wrap is too sharp and textured to make something like a photo look "glossy"... the gloss on photos is mostly from the light reflecting back and it mostly makes hotspots, not contours.
Experimentation is a good way to go though... better than a tutorial at first... just get to know the program... get a feel for it. Keep it up!
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