this this day I still can't do the stupid wall jump...
It's a ridiculously useful skill once you learn how to do it at least somewhat consistently.
I'm still working at it myself, but I've learned that it requires a lot of finesse. Very satisfying to pull off.
The idea is to jump at a wall until you're grazing it in the spinning motion, then push slightly in the opposite direction until you see Samus' "hanging" animation, and then press the jump button again. Samus only keeps the hanging animation for a split second so timing is everything.
The best advice is this: don't push away from the wall and press the jump button at the same time. You push away first, then jump once you see Samus wall-hanging, but it's still a quick motion.
What helps me is taking my thumb off of the d-pad once I'm grazing the wall, and then tapping away from it rather than holding down. Finesse!
In my current playthrough I accessed one of the rooms in Norfair that seems to require the Grappling Hook,
way before actually getting the Grappling Hook. Getting to it otherwise required wall jumping twice, first off a regular wall and then off of a platform edge on the left side of the room. Because the platform edge is only a sliver of usable wall space, there's only a small window of opportunity to pull off the second wall jump but it's entirely possible and when I hit it I was ecstatic.
In the end, it's all just for a minor expansion but hey, even the simplest of sequence breaks are really fun and satisfying.