So as kid many everybody seemed to have some sort of magic button inputs to catch Pokémon easier which is so cool because even without commecting on the internet everybody got similar idea personally the one at my school was spamming a then b what about everybody else
Clicking A right before the Pokéball reached the Pokémon then spamming B furiously while it was shaking for me when I was a kid xP
Pressing A as the Pokéball closed on the Pokémon, then pressing the D pad in time with the shakes (press right as the ball shakes once, left as it goes left, right at the 3rd, and down at the final capture 'click')
I used to think A+B and R+L right when the ball closed would increase the chances. I also thought pressing A for a Pokéball and B for a Great Ball when it closed would work
I used to just stare very intently at the shaking Pokéball to psychically force it to stay closed. Later on I kind of developed the habit of pressing A just as the Pokéball hit the Pokémon, then pressing A again when the ball snapped shut.