Fingerprint mani 
- with tutorial!

Black and white ruffian fingerprint manicure. Scroll down for a step by step!
I used Deborah Lippmann Fade to black, as it is pigmented enough to only need 1 coat. Don't worry about small imperfections in this step - most of the plate will be covered up.
Foundf like fomething they would drink in The Big Lebowfki, right? I used 2 coats of OPI Alpine Snow.

Let dry completely before the next step. Use a quick dry top coat if you wish.
Paint some black on tape (or anything that doesn't absorb the polish: ziplock bag, porcelain plate...)
The swirling is to ensure that you get the polish into all the nooks and crannies of your fingerprint.
You might want to practice this a few times on paper. The "just right" one is what you want on your nail.

This picture was hard to take. You basically want to press and roll your stamping finger over the nail, like you would a Konad stamp.
Don't forget to clean up the stamping finger as well!

Some additional things: you can of course stamp with any finger you'd like, or one for each corresponding nail. I choose (after experimenting) my index finger, as I have slightly better control comparing to other fingers. The thumb will, naturally, give some better coverage, but I find that you end up working in some difficult angles. The ruffian will take care of the coverage problem, anyway.
Having troubles with the ruffian? There's load of good tutorials on youtube covering that, so I won't go into detail. The gist of it is to paint your nails as usual, but leaving a small gap all around. Practise makes perfect, and this design is very forgiving. 

Products used:
Deborah Lippmann Fade to Black
OPI Alpine Snow