Jet if you think about all the details of a Pop up it is already too late!
By way of Illustration and showing just the major things happening you can learn to let your body just do!
These shots are taken at 12 frames per second so each picture represents 1/12 of a second think then react in that time, oops too late.
So what is happening here
A Eye line already looking where I am heading to for a small bottom turn then hands for B
B Hands flat on the board pushing down left hand putting slightly more pressure ( see the spray and slight board angle ) moving the board towards the bottom turn point.
C My forward right foot coming through led by the knee projecting me forwards and up in the next instant.
Another wave but same principles!
A Eyeline again with a much larger angle and Intention for a broader bottom turn not an angled bottom turn.
B Already popped up into riding stance knees under chest to stand up forward on the board not lift up the body over the feet backwards which would stall the board and ensure a wipeout.
C The actual line I will take before laying over into the bottom turn
D I still have a hand fingers placed on the board a slight tripod concession to my damaged knees , but still a one movement through and the forward weight gives me a little more acceleration into the wave.
Now the real objective here is that all these things and more are happening in a very short time frame so they need to become instinctive, having to think would be too slow.
You develop instinctive motor skills by repetitive skill drill training, keep doing, keep getting drilled by the wave.
Each time you succeed a bit your body muscle memory begins to build a template of what to do instinctively.
Takes time and intensive effort and is not as easy as the skilled surfers make it look. we have all done this Journey!

Also thanks to the Waikikikichan plan of learning lines on pictures idea

I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷