Putting limits on powersrs or conditions or combining minor powers etc depends on what youre writing

the steal what's cool elsewhere and put it in a blender method

Not main characters per say, but I derived my world's techs and combat aesthetic from irl world stuffs + colours. You don't need unique magic to make a guy interesting. 

Why do these powers need to be specifically cool and unique? Can't your protagonists be cool not because their powers are so unique, but because they're proficient (or just creative problem solvers) enough to do things few other people have figured out with the same powers?

Have you considered your protagonists thematically yet? Their origins, team role, cultural background, the source of their powers? Ask yourself what powers would fit them thematically... and what powers would feel off-brand, because adding something seemingly incongruent is a fun hook for further plots.

For one I based it around the saying "walk a mile in another's shoes" and what it meant to mean: you can understand a person if you see what they see.

So her power is that she can, after holding contact with the person for 20 seconds, go into their minds and "explore"/"experience" their memories. She could also do this to two people if she wants them to experience eachother's memories.

The point here is that you can based them around a idea or concept or even add in a unique twist to a already popular power. Like say they have super strength but is unable to use it for combat. Or super speed but they can't stop running/never tire. Things like that

Supernatural powers, abilities, magic etc are interesting when they are tied with characters' arcs and the broader themes (and metaphysics) of the setting.

You can come up with a million of new and original superpowers but they will keep being nothing more than a gimmick as long as the two conditions are not met.

I personally tend to approach powers or capabilities heavily as a metaphor. Just about anything can be Cool To Watch, or hear about, so to me, the important thing to do is think about "what kind of person is your character, and how they solve problems" and then use the powers as a way to talk about that.

This is where generic powers can be worked into something really cool and interesting, and I tend to start from the most generic framework and move in to specifics. The devil is in the details, and that's what makes it cool and unique. Think about highly beloved, interesting heroes- their powers probably AREN'T actually that unique, but it's how they're depicted, the narrative role they play, what they communicate about the character, that makes them interesting. So don't be afraid to start 'generic'.

To me, powers are narrative motifs more than anything else. Pick a couple of ideas that are very relevant to your character.

The main character of my personal fantasy project, Taylor, is associated with water. Ok, pretty generic. But they come from a subarctic island- so their relationship with water is that of an unforgiving north sea. They're also associated with darkness for bigger plot reasons, and they are essentially a trainee magical healer- a wannabe medic. So, to me, this creates a thematic profile for them: water + darkness + life, creates the image of blood, but also, the black smoker vents at the very bottom of the ocean. What nurtures life that is 'forsaken' by the sun and conventional world as we know it.

Tying in the medical aspect also gave me the idea of catgut sutures (not as gross as they sound- we've long made sutures out of organic material because we know that the body has an easier chance of absorbing it) so Taylor is someone who uses their own 'essence' to stitch people shut with their power.

I can go further into this but that's enough to outline my process. Basically, start with the big themes, and rough powers. In a team dynamic, what does this guy do for the team? Are they the 'guy that gathers information', 'guy that handles big heavy opponents', etc? This will also vary a lot based on what your team is doing. What skills are on display, if they're defined in individual niches or have more generalist overlap, will tell your audience a lot about the problems they're facing and the world they live in, if they're used to each other or were thrown together by circumstance.

Once you have their narrative 'job', dig into their relationship with them. This is where the juicy details can come in. Someone who has a power they use all the time, thoughtlessly, vs. someone who may dislike or dread their power or find it painful. The costs and benefits of the power, also, tell you about the character.

To come back to Taylor, giving them an ocean motif in a context where the sea can super kill you tells you that they are immensely powerful. That's actually a big part of their personal dilemma- this association with both the raw shaping force of the ocean, things as visceral and inescapable as the blood in your veins and the darkness that we require to sleep meaningfully- they're fifteen. They are fifteen and have only a homespun education in medical ethics and they have the power to bodily manipulate and shape people, and until they start getting into trouble it's never occurred to them that this power is horrifying and that they actually need to work very hard to not break people- either by killing them, losing their trust, or destroying them as a person.

Taylor is not a "good person" by default. Part of the point of the story with them is I wanted to build a sympathetic and likable protagonist out of conventionally villainous tropes. Taylor's name is even an allusion to that- the scariest bad guys are the ones that don't brush off the heroes but instead pay exacting, individualized attention to them. So that's where Taylor's personality comes from- they're a control freak. They're nosy, belligerent, and in that specific blend of teenage arrogance they think they know better than everyone how to make them happy forever. But this detail oriented obsession with people, also means they have a fighting chance to do way better than they're doing- the fact that they can one hit kill someone is both deeply internally upsetting, not who they want to be, and it also would make their problems way worse because they already have accidentally acquired a bad reputation as an evil person. A lot of their dilemma isn't "can I, with raw power, simply Win" but rather "how can I dig out the very specific, complicated heart of this problem without causing irreparable damage in the process?"

Nothing wrong with asking for help, but here's a suggestion to help you generate ideas: take a shower. Either it's the boring-ness and routine-ness of it or the white noise the shower generates, but I find that some of my best ideas spring into my mind when I'm in the shower.

Well, when you write a world it should be a unified, coherent whole, not just a collection of random parts. So, your powers need to be grounded in the world itself. Understanding them should give the reader/viewer deeper insight into how your world works, not just "those guys over there shoot lasers because why not, those guys over there can create fire constructs because I thought that'd look sick" etc etc. Powers grounded into the history of your world will make them more unique.

Secondly know what they can and can't do. Set boundaries on them and work within those boundaries. Know what the costs or requirements are to be able to use them, exactly what risks you run or costs have to paid, and what the upper ceiling is for each power. What's the difference between someone who's not that strong and someone who's very strong? Is it just how much force they can generate, or is it about being able to do it faster, more creatively, and outguess/trick the other user?

Not a writer but I figure most people just wind up settling for the meta superpowers. But picking the powers should probably compliment your characters or be used for character development such as someone whose power directly conflicts with a persons fighting style. My brother says levitation tho

English isn't my first language, so I use a grammar checker.

First of all, i think its called sci-fa Secondly i just pick powers i find interesting, knowing no power is unique. Its what you like since its your story