Not many words needed for this one. I just played around with several colors from the yellow to red spectrum on a nude background. I'm too much a perfectionist to like what I did here. The lines are not crisp enough for me... ^^; I sponged yellow and some light orange on the tips and then freehanded the lines with a striping brush.
And here's what I used, quite a lot actually:
I was surprised that I don't have a true red polish yet. They were all... different. :D