when life gives you lemons

...squeeze their juice on your freshly-mehendied hands add some granulated sugar, and rub those babies together!
This is one of the many tricks that Indian women use to get their mehendi (henna) to stay dark. Others involve holding hennaed hands over a hot tava (pan) with cloves and oil on the stove, falling in love, and sucking up to future mother-in-laws. It's rumoured that the more in love somebody is-- or the more her mother-in-law likes her-- the darker her mehendi will be.
The paste is applied from a paper cone, similar to the way people pipe buttercream designs onto cakes here in the US. Once it's sufficiently dry (people will sit and wait for up to 8 hours!), some girls add the nimbu-chini (lemon and sugar mixture) and rub their hands together, scraping off as much of the dried paste as they can. Then they wash their hands (no soap!, as my grandmother admonishes me every single time) to scrub the remainders off, and voila--pumpkin-tinged swirls on your palms. The colour darkens to a deep brown a few hours later, and lasts for a couple weeks. Some people use black mehendi, but it's chemically darkened and can do nasty things to skin. It's actually banned in New Jersey.
My least favourite part of the process is, obviously, when the mehendi starts to lose its luster. Your hands start to look diseased, or maybe like you ate a bunch of Doritos and didn't wash off the powder, and you have to hide them from everybody. When I was a kid, I wouldn't raise my hands in class for fear that people would make fun of the spotty faded mess. As I tweeted last week:

[My] mehendi is fading so my hands just look diseased. I find myself fist bumping instead of shaking hands & opting for self-checkout at stores. 

 Haylee getting her hands done in Delhi.

She left for Italy a few days later and later mentioned that South Asian expats in the country often stopped her to compliment/ask her about her henna!

Here are my hands, a few minutes after I washed the mehendi off. You can see how much lighter and more orange it is here than when the paste is on. It does darken up! I only left it on for about half an hour, since it dried so fast in the 110°F weather. When I go in December, I usually leave it on for about two and a half hours, so it shouldn't come as a surprise that thirty minutes wasn't enough time-- it started fading almost as soon as I got home to the States.

You can see how it's started getting a little darker towards the heel of my left (on your right) hand.

Mehendi is traditionally applied to the hands and palms of a bride (and, less intricately, to her close family and friends). Sometimes the groom's name is hidden in the designs--he can search for it on the wedding night and bridge some of the awkward shyness that must come with arranged marriages. So cute : )