Earlier quoted context omitted.
How have you strengthened your feet?
If you wear shoes without arch support and have flexible soles (or go barefoot) your feet with strengthen themselves by having to work just to keep you upright.
If it were socially acceptable to wear Vibram fivefingers where I work, that's what I'd do.
Since that's not really an option, I wear Puma sneakers (the 'replicat' line doesn't have a huge heel cushion) without an insert. And then at home I work standing up, barefoot.
If you're looking for new footwear options, a few places are now selling, ironically, 'barefoot' sneakers. [2, 3]
[1] http://www.dailymail.co.uk/home/moslive/article-1170253/The-...