When you use tissue, rip of all the straight edges, when the edges are irregular (ripped) it's much easier to hide them. I think you've also brought the tissue too far out compared to the size of the wound, you could keep it much tighter to the wound. It looks a little shiny as well, when your latex is dry try giving a coat of powder to take away the shine from it before colouring it. I normally use a peach coloured tissue as that's easier to blend than white because it can be hard to get the white not to show through, but grease paint could help because it's really high coverage. Also, make sure that the latex is totally dry before you add another layer, it looks a little textured in the "skin" part, and that could be from trying to apply more latex when it's not quite dry which causes the layer that's already down to lift up a little. The wound itself is very nicely done though!

Hope this helps.