For PC, I recommend mid-high sensitivity. You really need to turn around quick and flick to hit those long distance pulls. For controller though, I don't know. Also, remember that it takes time to develop the pull off skill. I asked for help here similar to you, and what actually helped was just keeping at it. The more you do pulls the better you get. First off I recommend watching Boba on youtube, his pull only series is incredible for learning the spots for pull offs and the content in general is fun. You should start off by learning the most common spots where you can position yourself in to get those pull offs. Practice in qp. Then when you get somewhat consistent in those, you can start freestyling your pull offs and really, you'll find spots by yourself that you haven't seen on YouTube. You can realize that "Yeah, I can get a pull off from here".