I was so happy with the result I got! The colors blend well, but you can still see that it's a gradient.
The way I do my gradients is, I painted the entire nail the pink color first, then I paint the pink and purple polishes directly onto a makeup sponge, and kind of gently rub the sponge onto the nail, keeping the pink on the bottom and purple on top. I do this after the base of pink is completely dried! That is important or you will get the sponge stuck and then the surface of the nail will streak or become bumpy.
I adapted my technique based on the tutorial you can find here...I just changed it up a bit to what worked better for me when I tried it. I highly recommend trying a holo gradient if you have never done one!