Though I say easy, the skill you need for this tutorial is: coloring inside the lines haha
Paint your nails with a base color
Creates lines in which you will color
color in one block on each nail
color the block on the opposite side like so
redefine the black lines, fix up any mistakes and add a clear coat
You could use diagonal lines and whatever design you like, make it complex, make it simple. I just stuck to this for all the nails I decided to paint on.