Absolute best thing I've found has been silk glove liners, and then cutting the tips off to make them fingerless. For some reason almost all the fingerless gloves you can buy cover half of the finger, not 3/4 of the finger.
I tried this but they get frayed at the ends, so you end up looking like a hobo digging in the trash. Ended up with some compression/arthritis gloves and they are just the right size, sewn at the ends, reach up to the last digit. But unfortunately they are made of some fabric that tries to minimize heat retention. So they only help a bit. Probably could be paired with the normal wool fingerless gloves.
Another factor is to keep the material thin between the fingers or it affects typing.
Wish I could design my own (sigh).
