I used to try to give myself reverse French manicures using paper binder rings -- it was effective, but not quite perfect (ok fine, FAR from perfect). Enter: Nail Guides, the easy-as-pie, even-your-Great-Aunt-Kathy-could-do-this mani tool. These particular chevron ones are made by the small Canadian brand Beyond the Nail.
Here's how they work: 1) Apply a base color and let dry (easy) 2) Apply the vinyl nail guides (totes doable) 3) Paint over with another color and peel off guides while still wet (victory is within reach!).
What you're left with is a very complicated-looking nail that will impress friends and strangers alike. There's a bunch of designs to choose from, so take your pick and get guiding!