Here is the mani, I will be showing you how I did.
The colors I used are Finger Paints - Tough Art to Follow & Savvy Green with Envy.
First you paint your base color, this can be ANY color you want. You need to make sure it dries though.
Then, I take scotch tape, and stick it to my palm. You will see later why I prefer scotch to painters tape. I stick it to my palm, so it takes away some stickiness, and doesn't pull up the base color.
Then I tape it onto my nail, in the desired design, here it is my diagonal design.
If you notice since the tape is clear, I can tell whether or not it is completely taped down correctly. So I don’t get any leaking underneath the tape. This is what it will look like –
Once you have it right, you paint your nail the other polish color –
Remember to do 1 nail at a time, otherwise the 2nd polish can dry to the tape, and pull up.
Once you're done, painting the nail, just slowly pull the tape off. Then do this to the rest and Ta-Da, you’re done.
I hope this helps, and is easy to understand. I'm not the best at explaining the process. If you look back at some of my past manis, you will see I use this technique a lot. I love my funky frenches, and for them, you just tape the nail off, leaving the tip open and free to paint the color of your choice.