I can't plan. I don't like it. I wing pretty much everything I write. I get an idea and I think about it for a while until I get super motivated to write it. Sometimes I'll drop ideas entirely. I had four ideas for this year and all of them are on hiatus until I can work out which ones I still want to continue. I get very into my writing and I love to think about it as I'm writing it. If I know everything and have it all mapped out, I can tell you now it would bore me senseless. I like to be surprised by plot turns and character development as I go along, like watching a movie unfold in my mind. I like to be excited about future outcomes, events and plot twists that sometimes won't even happen when I get there (The End did that a couple of times. It would have felt forced to keep them. If I'd had them written down in a plan, I would have had to restructure those parts of the story and figure out where to go next!)
I know planning works for some people, but it doesn't for me. I'm a pantser, through and through! I make some character and world building notes to give me a better idea of what I'm working with, but sometimes I don't even do that. I didn't make any character notes for The End until I was well into writing it and I don't think I did an ounce of world building except from what I had in my mind. It's a lot of fun for me to work this way, and it's why I won't start posting straight away when I've finished the first chapter - or first few. I like to have a good chunk written so the flow of the story is underway and there's a much smaller chance I'd have to change anything to keep continuity throughout the story. I jump back and forth making sure things fit, tweaking events, locations, characters. To use The End as an example, since it's the longest story I've ever written, Tinker's false eye and everstone didn't exist originally. I got the ideas and went back to add them in later. The story was originally set in a post apocalyptic world where the humans had been wiped out by the use of mega evolution. I scrapped that idea while writing it and made it completely PMD centric with no humans at all while also keeping a majority of the original ideas I'd had, such as the ruin but giving it a different purpose. I had to edit some of those human-inspired elements out while I was proof reading, such as neglected and cracked paving flags overgrown with weeds. As a result, the overall plot was massively transformed and I am incredibly happy with how it turned out. I actually miss writing it XD
It would be interesting to learn if anyone else works in a similar way. I'll have to go back and read over people's replies in this thread as I just kinda jumped in!