Wow, I'm a sewist/woodworker, too. What an awesome connection for a topic. I appreciate everyone's well-stated observations.
About the harder, more abrading, work altering the skin on our hands: I've taken to wearing gloves (and using work-arounds so I can leave them on) most of the time and following a strict lotion regimen. I've found that lotions having some type of glycerin and/or stearate listed _before_ the mineral oil work better at keeping my hands softer. It doesn't help all the way as I need to use the rubber studded finger tip grippers with some fabrics, but it makes a real difference. That's a little strange since glycerin and/or petrolatum combinations are also used as drying agents. I don't fully understand the dual nature of these.
At one point, it became difficult to match textures of fabrics and I knew I needed to change something. I at first thought that my skin was just drying out because I'm entering my 50's (which IS a small part of it all,) but then I noticed that my fingertips and parts of my hands were the most affected and I knew I'd have to mitigate the effects of wood and mechanical working.
As an example, after washing my hands and drying, but before they really get thoroughly dry, I'll lotion up - even if some moisture work around the house like moving clothes from the washer to the dryer is coming up soon. After each chore where my hands are dampened and I dry them, I'll use lotion, again. I keep a pump bottle at each sink and in the garage.
Also, like after a long bath or cleaning the sinks and bathroom with rubber gloves; if I let my skin dry directly from the shriveled prune-state without lotion, it toughens slightly.
To me, it's important for the wookworking, too; because when my skin is really dry, I can't feel the feathers of raised grain or the flush of an edge, for example, on a piece of wood unless I pull my sleeve up and use my wrist or the back of my hand. For awhile, I had to keep some synthetic satin or microfiber handy to drag on the wood to see if it pulled and rake a credit card across a joint to check the flush.
My finger tippy-tips seem to toughen the quickest and I have to alternate between working them down with a stone and peeling them if the callouses build up. Honestly, it's great for playing guitar, but troublesome for sewing and typing (I'm usually scanning servers and need to type amongst various keyboards by touch.)