Deus Ex: Mankind Divided Achievement/Trophy - Ghost (Mission One)
To get the 'Ghost' achievement/trophy, you must cross enemy territory without being seen. The best place to do this is at the end of Mission One when you make your way to the chopper. Before exiting the Elevator to the atrium, use two biocell items that will be in your inventory (One is in there by default and the other is by in front of the power box you switched on earlier in the level. Once you exit the elevator active your silent footstep and cloaking augments and run like hell to the chopper! You should reach the helicopter just as you lose power so once you interact with the chopper and get the cutscene, then your achievement/trophy will pop.
I have added a video guide below,