Keepingthem alive
Vegetable-tanned leather is a material, not a finish. It takes on the shape of your foot and the marks of where you have been, and it wants a little attention to do that well.
Suede
Brush it dry, always, and always in one direction. A crepe brush lifts the nap back after it has been flattened by rain. Never put polish on suede.
Smooth calf
Wipe with a barely damp cloth and let it dry away from sun. A neutral cream twice a year is plenty. More than that and you close the pores.
Monsoon
If they get soaked, stuff them with newspaper and let them dry slowly at room temperature. Heat is what cracks leather, not water.
Rotation
Give a pair a day off between wears. Leather needs about 24 hours to give up the moisture your foot puts into it, and shoes worn daily die in roughly half the time.