For me, it's simple:

1; warm climate, jungle, keep my shoes and bear wet feet (jungle boots or trail shoes)

2; cold or cool climates, sandals, sometimes I wished I had neoprene socks to add!.

But I never really hiked in winter condition with a need to ford rivers, just streams I could jump over, or risk a quick step through (still, Iceland's icy rivers fording is no fun, turns your skin purple, even in august <img src="/forums/images/graemlins/crazy.gif" alt="" />!)