Plinking doesn’t make sense to me.
I’ve always double tapped - but I guess it’s from being old… Not old school. Just old.
Stick - I agree with the playing beat-em-ups with it. Getting used to single direction movement (especially diagonals) and the occasinoal qcf type attack like in Streets of Rage really helped me out. That, and shmups. Helps you get your single directions more precise, so when you have multiple directions, it becomes slightly easier.
One other tip - when learning stick, pick a character that has a variety of move types. I learned 3S Remy for that reason: he’s got charges and qcf attacks. Chun’s another good choice for 3S. I don’t know much about SF4, but Chun has both of those types of attacks in that one too: her flip kick is a hcb and her fireball is a charge (I think) right?