SPD with a light set of recessed cleat mountain shoes. You can get off the bike and walk.
Used to use toe clips and cleats, but hate duck walking when I get off the bike on a tour. That kills Looks and SPD road shoes as well for touring.
Toe clips and flats (I had an old set of Adidas bike sneakers) are OK, but not fun to lose performance.
Can't imagine doing a loaded 60 mile day with sneakers on platforms.

'69 Dawes Galaxy about '89