I probably have the longest, most ridiculous writing process ever. XD
I obsessively re-read everything at least five times, probably more, and constantly change my mind about major events.
I imagine myself as each character as I'm writing them. I imagine the inner dialogue and what motivates them, as well as fickle things like what they had for breakfast and what underwear they have on. While I'm writing if I can't think of a word or how to connect two things, I close my eyes and pretend I'm one of the characters and act it out in my head.
I used to write with pencil and paper but recently converted to pages (like Microsoft word). I found that I lose traction easily with pencil because I start focusing on my handwriting and erasing constantly.
So I'll be writing and I start coming up with back stories and random ideas and scribble them into my notebook. Most of the ideas are insane and never come to fruition, so I have a huge journal full of sloppily written absurdities that even I never read. The journal is more of a black hole for all of my excess creative energy, and I'm honestly terrified to read anything in it.
I'm obsessed with research. Knowing every detail to me is important to my writing process so I find out what trees are common in the area and what they look like. And I want everything to be as realistic as possible so I start defining simple words like hat and cap, to better choose which I will use.