How to Make Your Own Latex Elf Ears (with Pictures)
Things You'll Need
Step 1:
Cut a hole in a piece of plastic wrap the size of a quarter.
Step 2:
Put the plastic wrap on the side of your model's head, pulling her ear through the hole. The plastic wrap will protect her hair.
Step 3:
Sculpt an ear tip onto her ear with nose putty. You don't need any tools; just use your fingers. Coat your fingers with a little baby oil to keep the putty from sticking. Try to follow the curves of her own ear to make the tip look like it is part of the ear and not just stuck on top.
Smooth the putty's edges into her skin with more baby oil and buff out any noticeable imperfections. Be sure to smooth the putty on the back of her ear as well as the front.
Step 4:
Gently blot the tip with a tissue to remove excess oil.
Step 5:
Dab liquid latex onto the ear tip with a makeup sponge, extending it onto the front and back of the model's actual ear. Allow the latex to dry, then add another layer. You want six to eight layers total, each one stopping a little higher than the previous so that the edge stays thin.
Step 6:
Powder the latex with baby powder to prevent it from sticking to itself.
Step 7:
Carefully peel off the latex ear tip, powdering the inside as you go.
Step 8:
Remove the putty from the inside of the latex ear tip.
Step 9:
Repeat the entire process for the other ear. If you feel comfortable, you can do both ears at once to save time.
Source...