My husband has a horrible time with that in the winter. He has horribly dry skin and it cracks--sometimes very deeply. We've learned some things and if he keeps up w/it his hands do pretty well.
1. Moisturizer can't add moisture to dry skin. It can only lock in what's there. So: first, always apply moisturizer to slightly damp hands. If the hands are terribly dry and there is just no moisture there soak hands in lukewarm water for five or 10 minutes before bed, pat leaving slightly wet hands, apply moisturizer. Some people find wearing wet cotton gloves at night with dry ones over really helps I've read. My husband didn't feel it was worth it.
2. Let the moisturizer (small layer, don't overdo it) sink into the skin. It takes about 5 minutes--more or less depending on how dry the hands are. Let it absorb. Then apply a bunch more on top of that.
3. At night do a thick petroleum based (if comfortable with that) or other very heavy type moisturizer like that you are comfortable with on top of the first layer of moisturizer. Aquaphor works really well here. He's also done petroleum jelly creamy.
4. Wear gloves at night and outside if at all possible to lock in the moisture. I read that cotton gloves work best but my husband is certain that the nitrile or vinyl type do best for him. I suspect cotton w/the other on top might be good and I suspect half the problem is how dry our house gets in the winter.
5. Wear gloves outside and minimize handwashing if possible (not possible here). Never use extremely hot water to wash hands (use warm), wear gloves for washing dishes to protect hands from hot water, etc. Apply moisturizer any time you wash your hands. You want it on there all the time.
I think chocolate is part of an excellent treatment plan, as in apply lotion, and eat a square of chocolate. 
