1) You can free-hand, which is what I did or 2) you could use striping tape, which I didn't have on-hand.
I decided that I was going to use my nail art pens for these since they are easier to control for straight lines, but I encountered a problem - the blue pen didn't show up on top of the black. To remedy this, I simply drew the lines first with my white nail pen, waited for it to dry, then colored them in with the bright blue. Boom, Tron nails.
These pictures are pre-clean up.
Also, I'm going to include pictures of both of my hands. Try to guess which is my dominant hand ;)
Black - Sally Hansen X-treme Wear #370 Black Out
White - Sally Hansen Nail Art Pen
Bright Blue - Sally Hansen Nail Art Pen