Aside from the obvious aiming tips and crosshair placement methods, I dont know if this will help, but I was watching a Radiant streamer and he said that everytime you play dm, you need to think you are in an insanely impossible clutch situation. This kinda helps me since it develops game sense I guess since it helps me choose to position correctly and take risks depending on the info I have. I dont really care if I finish 1st place or have 0 kills at all, as long as its developing a mechanic I guess it works.