I start out the day warming my hands, then gentle stretching and flexing, before I do anything.
I find I need to keep them warm (fingerless gloves are great), take frequent breaks, (gently stretch and flex).
In the winter, I have found that keeping them very warm while I am outdoors helps a lot too. If they get very cold, for very long, I am going to pay for it for several days afterwards. :D:D:D