China Glaze Cheers To You with W.I.C. by Herôme Gothenburg.
I think it looked pretty fun, although using a lamp here wasn't so handy as you can see on the photo above, it made it harder to see where the lines are. Oops! Anyway, here's how I did it:
1 Apply your basecolor and as always when working with tape, make sure it's completely dry. Cut strips of your striping tape, I usually put them on the side of my desk so I can easily take them off.
2 Start with one line over the middle, make sure to press the edges down well on the sides of your nails.
3 Then add more tape, have the edges slightly overlapping, but not as far that they stick out from other lines, if that makes sense. If you have your tape overlapping a lot (for example if you want a start-shaped design and everything overlaps in the center), try to remember in what order you applied them and remove them the opposite order later on.
If you want, you can use a small hobby scissors and cut off the edges of the tape now, add top coat and finish your mani with stripes of tape.
4 Work one nail at a time! Apply 1 coat of polish, if the polish usually doesn't cover completely in a single coat, just apply it thicker than normal, like I did here. If you would normally use several coats, I'd suggest to go for a different polish.
5 Remove the pieces of tape right after applying your polish (if you wait too long you'll pull up parts of the top color). I used a wide tweezers to easily grab and pull off the stripes. You can do it with your fingers as well, but the stripes will have polish on them and so will your hands then =)
6 After finishing a nail, repeat it for the next one, and when you're done with all your nails do a cleanup and apply top coat. As you can see on the last picture where I didn't use top coat yet, the top color will be higher on the nail than the basecolor. If you really want a smooth finish it might be needed to apply a 2nd coat of top coat.
You can buy striping tape online in places like BornPrettyStore and eBay. Hope this helps! :)