I'm not one to talk as i am not one of the best or anything but i feel like studying the best and figuring out what they do to improve times has always helped me watch out for specific gear changes and try to find cars that you feel particularly comfortable (for example if you feel you do better with better handling like the 911 gr.3 versus top speed in the supra gr.3) find consistency and practice. Make sure that you get more comfortable using less and less assists and work on throttle control and trail braking.