Do you mean: "What do you prepare to use when writing"? If so then for me the answer is a desktop computer.
Notepad and pen. For me, the blank white screen and blinking cursor is too harsh, too expectant. But when I pick up a pen, it's easier to start putting my thoughts down. The slow, manual nature of it also forces you to think slower. When given the time, my mind seems to better self-edit itself so that the words make more sense. I still find myself needing to go back and scratch out phrases that didn't work or add in missing details, but that will always be part of the process. I used to only try to write on a computer, but inspiration never lasted more than a page or two. The first time I tried writing something by hand, I had a dream that night of my story, and where it should go next. It was the first time I could remember dreaming in months. That dream was the wake-up call I never would've expected.
I prepare to write in laptop. Laptop is easy to use anywhere compare to computer. You can use laptop to write in coffee shop, park, hotel, mall, and restaurant. Laptop is so handy and easy to use. For me I prepare to use laptop in writing.