I don't use anything my hands are always warm, the girlfriend used zippo pocket Warmers though they work pretty well and keep warm for 10-12 hours if their filled up enough.
I bought one of these zippo handwarmers this year. So far I like it but they can be a little quirky. If you buy one watch a youtube video or two on how to ensure they are lit, etc. They are good to keep your hands warm but stink a little bit like lighter fluid. Overall I'd say good for steelheading as they will "burn" all day 8+ hours no problem.
Other that that some things I've found is to keep your body, especially your core, as warm as possible. If you are toasty warm then your hands will likely be fine too, however if you are cold then your body will reduce blood flow to your extremidies and then it will be very hard to keep your hands and feet warm.
For cold and dry weather I like my Simms windstopper gloves. You can fold back the finger mitt or the thumb if you need to tie a knot etc. However these gloves suck in the rain. Better to use thick wool gloves when wet. If super miserable out I will wear fleece lined waterproof neoprene gloves - they're super warm and dry! However a big pain to take on and off.
The Kast Steelheader gloves are suppoused to be awesome. EXPENSIVE but perhaps you get what you pay for. I bought a pair for an xmas present and if the receiver likes them I'll likely buy myself a pair too.
http://kastgear.com/gloves/steelhead-glove.html