Good question. I'm struggling myself to get past one minute, but my recent 52 seconds make me hopeful.
I find it difficult to find the right balance between staying high on the foil and keeping my speed high enough.
While I felt that pressing with my frontfoot is something I didn't do enough in the beginning (board kept climbing and slowing down and I would invariably end up in a wheelie-like stall), I now think that the secret of keeping going longer could be somewhere in applying the least pressure needed.
The rear foot kick sends the board up. Now all that's needed in theory is to aim the board in the right downward angle allowing your weight to accelerate the board on the way down. This would mean you would only have to apply a lot of force with both feet to compensate the forces generated during the rear foot kick, while at the highest point minmal pressure would be needed to point the nose down a little.
This is advice I have heard from some long distance foiler on the internet, but can't recall who it was.
As mentioned above, I'm not really there yet. Have to press with both legs right after the kick sometimes to speed the board up or to exaggerate the kick when I go to low.

Still, I guess it's worth considering as a concept and the mere thought of it made my last session my best ever after a long break.

I hope to get more input here as well. Who is willing to share the magic bullet of effortless pumping?

Might be a bit too simple (earlier in the pump journey) for you guys, but I like this recent video from Mark Shinn -

^^ You asking or telling?
Last two threads from you sounds like a bot.

trakkar said..
Might be a bit too simple (earlier in the pump journey) for you guys, but I like this recent video from Mark Shinn -

That is a good explanation. Helped me get a little further today.