If you're CROPPING to a smaller image size, leave an extra 2px on the width and on the height then use CANVAS size (not IMAGE size) to trim those pixels after you've cropped and resized otherwise you will have a transparent edge that LOOKS LIKE CRAP. I swear to god there used to be a way to make Photoshop automatically knock that shit off, but I can't for the life of me remember what it is.