I currently use Desert Essence coconut lotion, and it's remarkably effectivewhen I remember to use it. It's non-petroleum based, so it's safe to use after the henna is applied, and the ingredients are organic, so I feel pretty good about it. It also smells like total yuminess.
But in the days leading up to the mehndi, I'd like to go with a slightly more intensive hydrating treatment. Instead of my coconut lotion (which I'm going to try to get into a better habit of using daily!), I will be switching to extra virgin coconut oil on my hands, arms and feet (you can buy jars of it at Whole Foods or on Amazon.com).
It's solid at room temperature, but it softens starting at 76 degrees Fahrenheit. Conveniently enough, human skin is much warmer: I usually just grab a lump of solid oil and rub it into my skin, where it melts and hydrates quickly and effectively. I think that once-daily application of coconut oil (generally before bed, when skin loses most of its moisture) ought to go a long way towards healing my frequently dry, itchy skin. (The delicious smell never hurt anyone, either!) Extra virgin olive oil also makes a terrific moisturizer, but because it is liquid at room temperature, it tends to be messier.
What's your healthy skin regimen? Are you changing up anything before your wedding?