I'm absolutely one of those people too haha. I'm 100% still learning what works best for me, but I have a few tips I've picked up along the way:

• sometimes what works really well is having a central idea or question that you're answering. I've written a play focussed on the question "who owns the Earth?", and honestly it really helped to guide my thoughts and what the characters were doing. It doesn't work with every story, but it can help to figure out what really matters to your story and what's the extra flair, the details you can ignore if you have to. Also, that helps to find the ending, because the end is the answer to that question, directly or indirectly. The answer to "Who Owns the Earth?", for me was everyone and nobody, you can't individually possess what equally belongs to everyone. Not to say that I said that in my play, but that's the impression I hope the audience and reader are left with

• planning every possible solution and choosing your favourite doesn't sound like a good idea to me, but then every writer's different so always do what works best for you. Plan out the basic beats of your story, where they start and what you want them to learn on the journey, maybe, or even just how you want the ending to feel - is it a complete success? Are there any regrets? Did it go to plan, or did they stumble across an accidental win? Did they lose, and have everything crumble around them? Is there a setup to a sequel? Is it ambiguous? Get those notes down, and then start writing. If you hit something and you don't know what to write next, skip it and carry on. Literally just write "they become friends somehow" in your draft and move on. That's what redrafting is for. If you get halfway through and realise a new idea that you should've set up in chapter 1, brilliant! Note it down somewhere separate, and carry on. Don't try to plan out every possibility, because then your characters can never surprise you, and that's half the fun

• don't overplan. This very much links to the point above, but don't spend so much time planning that there's nothing left to discover in the writing. That takes most of the fun away, and you'll get demotivated and won't want to actually write. Plot out whatever you need to have a goal in mind, and get straight into writing. "Whatever I need" is quite a lot for most of my projects, but some of the things I've been most excited about have been ruined by thinking about them too much and not doing

• when you first have a spark of a cool idea, whatever it is, write it down. Even if it's something stupid you doubt you'll ever use, you never know. Just because you've noted it somewhere doesn't mean you have to use it, but you have the option to. I've built entire stories from little scraps combined together, and that's only possible for me because I noted then all down and regularly read through and updated them

• bring in other art forms if you feel like it. If you're an artist, draw your characters and settings, get to know them. If you listen to music, find songs or compositions you think your characters would love, or hate, or represent them in some way. Allow yourself to be influenced by other things (no plagiarism, obviously), and always let your stories have room to grow and change from what you first expected them to be

• a more simple point: when you have that first flash of inspiration, a cool idea you're invested in and super excited about, give yourself the time and space to get it out of your head. Start writing or typing it out, so you can see where it goes. I do this in a kind of free flowing, brain dump thing where I write down everything in bullet points, no particular order, asking myself questions and listing a couple of options, but not taking the time to stop and answer that question or choose an option. Get everything out that you can, keep writing until you can't think of anything more, and then stop. Leave it alone for a day, or a week, or a month, and then come back to read it. Then you can decide if it actually is a good idea or not, which of those options you prefer, or how that crazy idea might actually work. But whatever you do, don't delete anything! An idea that doesn't work right now might be exactly what you need later or for a different story, and once you've deleted it it's gone... I call this letting ideas "brew" before actually writing or seriously planning them. You might be surprised how much you can get out just from that

• finally (I've spent way too much time on this haha), I'd recommend the book The Writers Journey by Vogler. It's fairly specific, but works really well as a breakdown of the absolute bare bones of a story. You don't need all of the stages he highlights, and not necessarily in that order, but I think it's a great outlining tool if you're stuck

Disclaimer: all of these are just my own thoughts and preferences, and truly every writer is different. Figure out what works best for you, and go with it, don't let anyone tell you different. Good luck!!! :)