*Please note that this solution contains Very Minor Spoilers*
For efficiency, its best to use an Engineer class to complete Sabotage, Neural Shock, AI Hacking, Damping, and Overload on one character. However, for this trophy, you can also use an Infiltrator and Sentinel class. Sabotage requires at least 1 point in the Decryption skill, which is immediately available on a new character.
Important: This trophy does not require a target. It can be cast on anything, anywhere.
The easiest way to obtain this trophy is to cast the skill whenever it's available, even if you don't have a target. You can do this while walking around the Citadel. Just wait for it to recharge and cast again. Additionally, if you have a few extra skill points, put them in your class skill to somewhat reduce recharge time.
Final note: Only Neural Shock and AI Hacking require specific targets. Other Engineer skills can be cast into the wall/ground/air.