Some people do very well with their hands at cold temperatures when skiing and other people do poorly--buying a variety of heavy mittens and gloves but never finding anything that keeps their hands truly warm. Mountain bikers who use their bikes on snow have made "poagies" which go onto the ends of their handlebars to accommodate their hands for steering. They are essentially large bags that are insulating and windproof that allow easy access to the control surfaces with hands not encumbered by gloves. I have adapted this scheme to the tops of ski poles which allows you to grab onto the handle without trying to jam a huge glove or mitten into the strap. This ski poagie can be used for both x-country and downhill. For me it has been wonderful to ski for hours at -10 and never be bothered by cold hands. I was one of those people who tried everything and thought I would have to give up skiing because of my hands' intolerance of cold temperatures, but now I just place my bare hand into the sleeve and am totally comfortable.
The poagies are made of windstopper fleece material that is cut from a pattern and sewn together on a sewing machine. The poagie allows just enough room for your arm and the ski pole to enter and not allow air movement. The design depends somewhat on the size of the ski handle and the amount of insulating layers you want to use and should be modified accordingly.
Step 1: Gather Materials
You need some windproof fleece material. This is readily available at fabric stores that sell fabric for outdoor gear design. There are large varieties of this fabric but asking for "windstopper fleece" should get you going in your hunt. You want a fabric that doesn't allow the passage of cold air yet insulates well and allows the moisture that you build up inside to leak out. You don't want anything that is unbreathable and plastic coated. I built my poagies of two layers of this fabric because I needed more insulation--depending on the thickness of the material you may opt for one.
Sewing Machine--you don't really need one if you can hand sew it--but it sure helps for neatness.
Wife/Girlfriend to sew these things--if you're female you probably know how to sew--I never got this training so spare your partner a lot of grief and don't try to use this machine for the first time by yourself on thick fabric like this stuff.
Step 2: Pattern
You can use the pattern I have layed out above and then compare it to the size of your hand and arm and see if you want to modify it. The opening for the shaft of the ski pole is quite small and I have to work to fit the pole and hand strap through. The arm length of the sleeve is quite long but this allows it to be windproof and insulating without constricting which is what you want to avoid when you are swinging your arms skiing.
Step 3: Cutting
Lay out the pattern on the fabric and outline with a marker. There is no tricky right versus left or inside versus outside for this simple design. If you want single layer poagies you just cut out two of these patterns and sew them together. If you want double layer poagies you have to cut out four of these for each poagie.
Step 4: Stitching
If you know how to sew this is an easy step you just sew the two halves of the poagie together--not sewing over the two openings. You work on the inside of the poagie and then turn it inside out and you're done. If you are making a double insulated one you have to fully join the two layers and then sew the poagie design with the openings as noted. I have since modified the design slightly--sewing a piece of elastic cord on the top inside to tie the ski pole in place and keep it from migrating.
Step 5: Enjoying
Hey, it's winter--cold and dark and anything that enables you to get out and enjoy it is good. Please write me with any modifications that you can suggest and I hope you make them. Trust me, with these your hands will never be cold again.