Was paying attention last time out as to what I do to gain balance, as I said before I look at the board (nose mostly) when on the water and starting out in waves, but then I noticed even in-flight if I needed to regain balance I did it by looking at the board, but just for a split second, since that is all it takes for me to regain balance. And really, if I do not regain it right away I would crash when in-flight.
That's interesting, we have opposite experiences. I don't foil but for when slogging with fin, i usually lose balance if i look at my board, and gain balance if i look at the horizon or somewhere far. Similar for jibes with fin, if i look at my board (or rig) i fall 100%, need to look at chop 5mt away for suspension but otherwise i would prefer to look far.
Last summer i bought my father a sup to improve his balance, at first he struggled to stand up while he was looking at his board, he was much better after "look at the horizon" advice.
Best way to improve balance is to choose a more stable platform or.... lower center of gravity, extend arms out and look away at a fixed position well away from you.
To improve balance in regards to a specific situation, repeat the situation daily, applying rules above, and get good night sleep!
Shouldn't you feel your backfoot position by the toes (rail) and the outer edge of your foot (backstrap)?
If you have straps on your board, yes. I don't use straps. Never saw a reason to use them with freeride foils. As for feeling the rail, that does not work due to a very round rail, booties (necessary at many places I foil, and always good in accidental foil contacts), and the board being 85 cm wide. A balanced position is key, and since my front foot is usually in a bit more, the back foot does not need to go all the way to the rail - it just needs to be far enough of the other side of the center line. All the way to the rail can be unbalanced. In GoPro videos, I've caught myself first stepping far to the rail, and then moving the foot back a little bit towards the center. But the common problem was not stepping far enough, with the back heel on or barely past the center line.