Those are extremely easy appliances. You have the right idea.
Cast your face (any part you may want to do appliances for...full face is best if you have some help). I use alginate for my casts as I only plan to make one pull from them and it is far cheaper than silicone. Use a good, solid material like Ultra Cal or such for the actual casting material so you will have the sculpting surface for YEARS (mine is at least 5 years old and I think older and has survived some rather nasty beatings and droppages
). Then sculpt whatever you want as an appliance and recast that. For that part, I tend to use Ultra Cal or just plaster of paris (if I doubt I will need many pulls).
Get yourself some good, mask quality latex like RD 407 (my personal favorite) and layer it into the mold you just made of the sculpt. Many thin layers are the key as latex only dries so deep when exposed to air and can leave liquid (guts) if put on too thick. After you build the latex up to close to the depth of your face (and it has all set nicely), carefully pull the new appliance out of the rigid mold and use something like Prosaide or Beta Bond (I prefer Beta bon, myself) to attach it to your face. Latex can be tinted with acrylic paints and painted afterwards with special paints, acrylics, or even acrylics mixed with a small bit of the Beta Bond (not advised unless you plan to paint it on SOON and FAST
). When done, just peel it off and clean your face with a good adhesive remover (my preference is Telesis Super Solve...same guys that make Beta Bond).
