hiii wow this is so kind thank you so so much for such a lovely message（๑ ᷇ 𖥦 ᷆๑)♡
this is not too much of an ask at all! i love talking about writing so much. as for planning. i am a bit of a mess when it comes to planning hahah so i don’t know if i give proper advice on that, but maybe its a method that works since its worked for me ? when im writing a longer fic the idea almost always sprouts from me visualizing one specific scene and building the fic and plot around it, or maybe a specific dynamic that i want the characters to have. i usually start with writing this scene first just for fun and it makes me excited and i can build around it. it usually goes thru a bunch of edits afterwards anyway, but it gets the thoughts going. aside from that, i just think about it all the time. when i’m reading, watching something, listening to music, i’m finding parts of my characters and story in these things. i write all of these thoughts down!! my planning pages, if u could even call them that, look ridiculous, but its best for me to just get my thoughts out. since i always finish drafting my chaptered fics before uploading, i am able to write out scenes as they come to me and sort of fill in the spaces around them (im sure this is where the purpose comes from that you were referring to). this allows me to draw strings to different points of the story and connect them! theres a lot of writing down random things just to get my thoughts on paper. the more you think about your story, the more that will come to you!! my longest fics weren’t rly supposed to be so long usually but i just kept thinking of ways that i wanted to expand the story. when you’re reading and watching long-form media especially pay attention to the storytelling tools that they use. research narrative crafts and dissect your favourite stories. eventually, you will see this path in ur own writing. i will always chat about my fics if you’re curious about that stuff with my writing, but for all other stories there’s usually tons of digging already done! its one of my favourite activities haha so maybe thats how ive built the muscle.
i hope that answer sufficed!! ilu anon thank u for reading and ur sweet thoughts <3