As long as you make sure the end points are valid, this is most intuitive for me. Just using i as a backwards step.

for (int i = 1; i <= N; i++) {

    array[N-i]

}

Conventionally, loops with <= is very much a Pascal thing, not C.

This fails on overflow: if N == INT_MAX then your loop doesn't terminate and actually invokes undefined behavior in C.

The safe way to write it is:

    for (int i = 0; i < N; ++i) {
        something(array[N - 1 - i]);
    }