Yes, I write by the seat of my pants, and I love it that way. It brings me joy.
My best ideas about whatever I’m writing (or planning to write) often come when I’m not actively writing. I daydream as I relax or as I’m doing chores or other tasks. Sometimes it happens in the middle of talking when something in a conversation sparks an idea. If I’m ever speaking with someone and reach for a pen and paper that’s probably what happened. Sometimes I quickly text things to myself if I don’t have anything handy to write with. The thoughts and ideas can be so fleeting, like dreams, so I have to be quick. I try to do it politely because I know if someone did that to me more than once I’d get irritated.
Then I have a more formal notebook I gather them in if I haven’t already incorporated them into the story. I might input them onto a novel spreadsheet I use to organize unused ones for future use (I do love spreadsheets best).
I have found writing to be a messy process if I don’t stay caught up, but I’m learning to better organize those ideas by incorporating some of my old left-brained project management skills over onto the right brain. I know scientists now say both sides actually work together but sometimes it seems like the balance knob doesn’t work or something.
I’m still a work in progress, though.