I've never done a tutorial before but decided it would be beneficial when I'm posting pictures of my nail art. I'm starting easy with just a simple design featuring two colours...
Pick two different colours, preferably a light one and a dark one. I used Barry M Gold (289) for the base and Barry M Indigo (312) for the tips.
Paint entire nail with the lighter shade and leave to dry.
Paint top of nail as picture below. If needed do two coats. I found it easier to go from each side to the centre of the top of the nail rather than attempt the full pattern in one go.
Repeat for all nails.
Seal with a top coat and clean up the edges using a cotton bud.
This look seems to look better one longer nails than shorter ones. Also it might be easier if you use a nail art pen to make the lines neater.