Some Ombre Eyeliner Inspiration:
Start with the lighter shade, then when you apply the darker shade, start from the outside and work your way in with light strokes, then use an eyeliner brush to blend the colors where they meet. If you're using liquid liner, blend the liquid into the lash line where the colors meet so the start/stop point isn't so obvious.
Ombre Eyeliner is super cool, no doubt, but the newest trend now is 'Two Tone" Eyes, where two colors are blended or placed tom and bottom on the eyelids to add drama
Two Tone Eye Inspiration:
Grab some Urban Decay 24/7 Liners ($19 at Ulta and Sephora) to start creating these looks