Here's what you will need for the design: base colour (e.g. Emerald Green), red glitter, red sequins, cover coat.
Step 1: Base Colour Emerald Green
After applying a clear coat of UV-Gel (or regular nail polish), put on your base coat colour. I chose to go with this Emerald Green coloured UV-Gel, which is one of my favourite colours, since it shimmers gold, green and blue depending on the lighting. This design will of course work with any other base colour of your choice, but I just felt the red and green contrast, the forbidden colour combination, worked well and it will go well with my hypothetical costume of Elphie from Wicked - if I manage to find the items I need. I could also see black working well or even a very innocent pastell blue.
Step 2: Red Glitter Dust Coat
Step 3: Creating Blood Drops
To make the red tips of your nails look like actual blood you need the larger red sequins. Use some more UV-Gel (NP) and paint a thin strip the way you want the blood to run. Dip the sticky brush into the sequins and arrange them to look like dripping blood. After this has dried add another protective layer of clear UV-Gel or polish and you are done. if you are using gel, another layer of clear nail polish really lets it shine.
Nail Polish vs. UV-Gel
If you want your design to really last and be robust - maybe not a bad idea for a Halloween Party - using the UV-gel is the better idea, since it is (almost) indestructible. It also means that with the top coat you are really sealing in the glitter and those sequins, so the chance of them dropping off or sticking out are minimal. However, using UV does mean you need the UV lamp first of all. And it tends to end up a lot thicker than with nail polish, especially if you want the surface to be smooth. Using nail polish, getting a smooth nail with all of that glitter is almost impossible. I cannot live without gel nails anymore, but if its just for Halloween, using polish is maybe the better option.
Check out this page for some UV-Gel enthusiasm. Happy Glittery Halloween!