The fastest way of gaining the skill achievements (Lift, Warp, Sabotage, etc.) is to stand outside the Mako and use it for a target. Do each skill with your current character 75 times to get the achievements for each one. However, two things must be noted. First off, Neuroshock does damage to the Mako. When you see it begin smoking, repair it. Second, AI Hacking does not apply at all here and you must actually hack 75 AIs or hack a few repeatedly before you must destroy them. The best way to get this one is to play the mission where you must go to the Earth's moon, or "Luna", and stop the AIs in the training facility. Save the game before you go into one of the bunkers and keep hacking them until you are finished, or reload and play again.