I do it from scratch, and I use the process of "the ideal/best ___"
Like the best swordsman would be a serious character, not some goofy comedic character, and then I go from there
Of course this only really helps me come up with a character.
For the writing of the character itself, I just kinda...
I just recently remembered all those movies I see in bins for sale are bootleg movies and other garbage (for the most part) and honestly I feel stupid for only now snapping back and remembering "Oh, those are bargain bins, right." Its such a random thing to forget.