Mostly it's illusion powers. He can change his appearance, anything from a new outfit to a perfect mimicry of another person - good enough that he spent months or years ruling Asgard as Odin. And the changes of appearance seem to be more than merely visual - they have physical form.I've never been super clear what Loki's powers are. He gets beaten up by everybody, but he can change his appearance (which he does rarely)? As gods go, he's never felt very godly. He's not really very powerful. But he's always been fun to watch.
He can also become completely invisible, and project a false image of himself elsewhere. Quite some distance elsewhere, it seems - he was able to appear to be in the gladiators' quarters during Thor Ragnarok while he was still partying outside. That also implicitly includes the ability to perceive areas at a distance.
When he was incarcerated in the second Thor movie, he was able to alter the appearance of his entire cell, projecting an appearance of himself calm and collected, to disguise the ruin and despair he'd wrought after learning of his mother's death.
He probably has a few more miscellaneous tricks of magic that he learned from his mother.