I wanted to do something fun but I wanted it to be easy too. Geometric patterns are totally in so I decided to do color on a diagonal. Now I definitely don't have a steady hand, especially when using my left hand so those french tip strips were the bomb!
Check it out:
Paint a base coat, let it dry completely... a good 15 minutes or more. Apply the french tip strips on a diagonal (I'm not sure what else would work just as well, but I'm thinking small pieces of painters tape would be great)
Apply the second color being sure not to go completely over the strip
Carefully remove the strip when the color has set for about a minute or so. There will be a tell-tale line that has a bit of an indent, but no worries about that. Apply 1-2 coats of a top coat and it'll all be glistening and smooth!