Exploiting Sprite Animations
All of these techniques are performed while unmorphed, with the first three involving the angle buttons.
Any time Samus morphs, unmorphs, or turns around while unmorphed, an uninterruptible sequence of sprite changes is initiated. These have some useful applications for speedrunning.
Firing a shot is also an uninterruptible animation; this is commonly used in areas where you lay a bomb, then go through a morph tunnel, and want to avoid the bomb jump effect. Applications include Below Spazer, descending Bubble Mountain, and destroying the statue in Red Kihunter Shaft on the way out of Lower Norfair.