writing

How do you write? What processes do you go through? Do you have a plot and everything rougly outlined in your mind, or do you make it up as you go but knowing that you want to write for the sake of writing? Do you just sit down and start writing, free-flowing, and fix any grammar mistakes later? Do you write in short installments - stopping frequently and coming back to the piece, or do you have to write a good chunk before you can leave the computer? Do you talk with friends online and discuss ideas/plot/logistics? If so, where can I find these friends? :p