I comlpletely lost my focus on dorsiflexion at the start of our season and had to train my self to consciously remember it !! Even though I have pretty bad dorsiflexion when I do remember boy oh boy does it make a difference.
As an avid walker/hiker I've been focusing on your advice of finding that heel arch which will hopefully translate when I get back on ski's (fingers crossed this coming week) but now I'll also add dorsiflexion into the mix.
I think about this stuff every day. Since we're on the topic, here's one more thing I'm working on.
I pay attention to where my feet are relative to my center of mass. Now center of mass is not something I can pinpoint as I walk or run, or ski. Not with the specificity an engineer would like. But I can feel whether my stance foot is out in front of me or under me or back behind me. The "me" in that sentence serves pretty well as my center of mass.
When skiing, my feet need to stay either under or behind "me." NOT out front of me. I can easily feel where they are relative to "me" when on snow. Keeping them back, not out in front, assures me that I'm not skiing in the back seat. The same goes for walking and running. The term for planting one's foot on the ground out in front, when running, is "over striding." It's a no-no. It produces high impact on the knees and slows one down. The foot needs to be planted beneath the runner and extended back.
The problem arises, "over striding" on dry land, or skiing in the back seat in snow, when one is heading downhill. It feels insecure to keep the feet back. Having feet (or foot) out in front feels secure. On snow, giving in to that sense of security causes one to lose the usefulness of the front half of the skis. Control of the turn slips away. Giving in on dry land causes one to put those knees in danger of damage from repeated impact.
Practicing paying attention to where the feet are relative to "me" when walking/running, especially when going downhill, and practicing keeping the foot plant under me then extending back, is great practice for skiing.
All that stuff about arch-heel and dorsiflexing and pulling feet back and pointing the arrow etc complement this. It's all connected.
There's commitment to do it. I've got this.
Then there's forgetting to do it. Losing focus. I have to work on this constantly.
This is very nerdy talk. I'm glad to find some folks can tolerate this type of discussion.