Pick a fun line of dialogue and just cut it there. End the chapter or plonk in a scene break and move on.
Interrupt whatever's going on. You can customize the interruption to the genre of your fic, but it could be as simple as a phone call or a knock on the door or as complex as a parachuting velociraptor wielding a machete. Now your characters have to deal with *that* instead of wrapping up whatever they were doing before.
Find a parallel to another character who isn't there and use that as a transition to write about them in *their* scene. Two characters are mourning the end of their relationship? Smash cut to another character looking at a photo of a lost loved one. Character is in an angst spiral over a decision they need to make? Switch over to someone staring at a coffee shop menu in confusion.
Change the perspective. There's a fight going on and you're tired of writing it? Well, now you cut to a character on the other side of the wall who can hear some weird noises. They can choose to investigate or ignore, as you see fit. You don't want to write smut but your characters are making out pretty heavy now? Their roommate in the room next door decides now would be a great time to take the dog for a walk.
Get to a moment of tension and just... stop. End the chapter. Congratulations, you just wrote a cliffhanger. You can pick up the next chapter at any point you want (conveniently getting you past the tricky thing you weren't sure how to write). Bonus: you might have people yell at you in the comments 😈
Ending a scene early is a great way to get yourself out of a block. Conveniently, it's also an interesting way to write a story.
Feel free to add more ideas in the notes.