Climbing hills: Where have you found the most beneficial foot position on the pedals?

[Flowrider]

I don't have clip-ons and I mountain bike 90% of my rides.

Over the years, I have experimented with my foot position on the pedals when climbing hills.

I've tried with the pedal on my forefoot and with it in the middle of my foot.

Where have you found the most benefit with your foot position on the pedals?