In magical handwaving science fiction, a frequent trope is the unexplained power of the mind. Characters can move objects or read minds without any real scientific basis. It's just part of the 'handwaving' aspect. Another is the existence of parallel universes that are easily accessible through some magical or not - really - explained - scientifically portals. And the 'deus ex machina' endings are also common, where some unexpected and not - fully - explained force or character swoops in to save the day.
Well, time manipulation is quite common. Characters can go back and forth in time just by waving their hands or using some sort of magical device. And the concept of 'instant knowledge'. A character might suddenly know how to operate a complex alien machinery just because they have some sort of psychic or magical connection. There's also the idea of 'cosmic forces' that can be harnessed with little effort, like a hero using the power of the stars to defeat a powerful enemy.
One common trope is the sudden appearance of advanced technology without much explanation. For example, in some stories, a character might pull out a device that can instantly teleport them across the galaxy. Another is the use of 'handwaving' to explain away scientific inaccuracies. Like when a spaceship travels faster than light with just a quick mention of some new, unproven energy source. Also, there's often the all - powerful alien or wizard - like figure who can manipulate reality at will, which is a staple in this kind of science fiction.