Step 1: Bloody
Using a toothpick, draw on your blood at the tips. I couldn't find any toothpicks, but did have some extra birthday candles lying around that actually worked perfectly!
Step 2: Monsters
With a fine-tipped black polish pen (or toothpick and a steady hand) draw on the hair around the cuticle. Fill in.
Add X's for eyes and a stitched in looking mouth.
Step 3: Jack-o-lantern
Using a toothpick, fine-tipped brush, or candle, draw on black triangles for eyes, and squiggles for mouths. Have fun and mix it up with each finger!
Step 4: Chattering Skulls
Paint nails black.
On one hand, paint the top of the skulls. Fill in white circles extending to the tips. Once dry, use your fine-tipped brush and paint on the eye and nose sockets. Along the tips of the nails, make tiny dashes as the spaces between the teeth, then draw a black line above to finish out the gumline.
On the other hand, draw a thick white line a bit below the tip of the nail. Then add little white dashes on the tip and you've finished the bottom of the jaw. Depending on the length of your nails, draw 3-4 small dots as the vertebrae. Make small white dashes on both sides as ribs, leaving one dot along the jaw as the "neck"
And you're done!
Step 5: Other Ideas
Have a fun Halloween, and feel free to comment with pictures of how your nails turned out.