OP, I have no clue what your definition of "longer hill" is, but for the long gradual hills of central NY I do the following:

Look around. Focusing on anything other than the climb helps me.

Keep my upper body relaxed, and breathe as normally as possible.

Sing. I prefer "The Battle Hymn of the Republic" on climbs over 3%, but have a medley of They Might be Giants at my disposal for lesser grades.

Only stand once, and I am committed once I do.