Shake the liquid latex bottle for 30 seconds.
Pour some liquid latex onto the sponge wedge. Dab the wedge onto the area where you want the blisters to be. Leave to dry.
Dab more liquid latex over the first coat and leave to dry. You can make the blister with two layers or add a third for thicker blister skin.
Pinch the center of the latex skin gently between your thumb and forefinger and pull it up. Work carefully so as not to rupture the liquid latex.
Pull the latex up in the middle until the center creates an air pocket. Keep pulling until the blister is as big as you want it to be.