This section will provide additional tips on how to unlock the listed trophies. There are no missable trophies in the list since the game allows you to conveniently replay any previously played chapters, down to specific checkpoints. There are also no difficulty-related trophies so you can attempt all of them even when playing on Easy mode.
Trophy progression like the number of kills are retained even when you're restarting a checkpoint so use this method when farming for kills in an optimal area. The best location to farm kill counts is during the large courtyard firefight in Chapter 3 (The Puppet Queen checkpoint) or at the start of Chapter 8.
The Marksman
Kill 5 enemies with a headshot during Blacksight
You'll learn the slow-motion ability called Blacksight as early as Chapter 2. You only need to kill 5 enemies via headshot while in Blacksight during your whole playthrough. This regenerates over time so use it whenever you can to unlock this trophy.
Well Rounded
Kill an enemy with every weapon
The game has 17 weapons, including one explosive grenade. You need to kill at least one enemy with each and every one of them. Most of these weapons will be given to you as you go through the story but make sure to check the bodies and use new weapons to kill at least one enemy. Sadly, there is no tracker in the game about your progress for this trophy. The list of the weapons you need for this trophy and the earliest time you can get them is found in this link.
Modern Marvels
Kill 40 enemies with science weapons
Science weapons are the ones developed by Tesla (TS models) and you'll get the chance to use them all as part of the story.
Collateral Damage
Kill 3 enemies with a single explosion
This is during Chapter 8, (A One Man Army checkpoint) where you'll get a chance to use a rocket launcher you'll acquire from a fallen enemy. As soon as the checkpoint starts, you'll have the chance to blow up three enemies near each other to the bottom right. You're free to restart the checkpoint if you want to attempt this again quickly.
Between the Eyes
Kill 100 enemies with a headshot
The best way to farm this is during the large courtyard firefight in Chapter 3 (The Puppet Queen checkpoint). It's recommended to do this along with the Gunslinger trophy (Kill 75 enemies using a pistol) since they have very good accuracy and stability especially when properly aimed. Since the kills towards the trophy unlock is retained even if you restart the checkpoint, you can just keep on reloading before you kill all enemies.
Undivided Attention
Kill 25 enemies during Blacksight
You'll learn the slow-motion ability called Blacksight as early as Chapter 2. You only need to kill 25 enemies while Blacksight is active during your whole playthrough. This regenerates over time so use it whenever you can to unlock this trophy.
From the Hip
Kill 25 enemies without aiming
As the description says, you have to kill enemies without aiming (R2). This can be done while standing or while you're in cover.
Box Your Ears
Kill 15 enemies with melee attacks
Silent takedowns don't count towards this trophy. You really need to get up close and personal to the enemy and press Triangle to perform a melee takedown. It's recommended to do this on Easy mode since you'll be able to survive close enough to perform a kill. Just restart a checkpoint to farm this easily.
Snuffed Out
Kill 7 enemies with silent takedowns
Only the silent takedowns done after the game gives you a tutorial will count towards this. There's a lot of silent takedown opportunities in Chapter 5 and Chapter 11.
Gunslinger
Kill 75 enemies with pistols
Chapter 8 is a good farming location since you'll start with the Dragoon revolver (capable of one-shot kills) and there are multiple enemies. Another good farming spot is in the large courtyard firefight in Chapter 3 (The Puppet Queen checkpoint).
The Hunter
Kill 10 Lycans
You'll encounter several werevolves as part of the story. You need to weaken them by riddling them with bullets while evading them at the same time. When you've done enough damage, they'll be vulnerable on the floor. Get up close and finish it.
Up in Flames
Incinerate 15 enemies
Only kills from the M86 Thermite Rifle will count towards this trophy. The best place to farm kills is when your first acquire it. (Chapter 3, Rebel Contraband checkpoint)
Inspector First Class
Find all inspect items
You must find all the other collectibles except the Phonograph Cylinders since these are counted towards a different trophy. See this link for more details.
Archivist
Collect all phonograph cylinders
You can track the phonograph cylinders you have collected by accessing Archive from the game's menu.
See this link for more details.
Well-read
Inspect all newspapers
See this link for more details.
Detail Oriented
Inspect all photographs and documents
See this link for more details.
Power of Observation
Inspect all objects
See this link for more details.
Brilliant!
Shoot an airborne grenade during Blacksight
The good thing about this trophy is that you can shoot your own grenade, regardless if its the frag or smoke one. The best place to attempt this is during Chapter 3, The Puppet Queen checkpoint since you'll start with some grenades. Find an open space and throw the grenade up. Quickly activate Blacksight to auto-aim at the grenade and shoot it.
Discombobulated
Stun an enemy 30 times with the M2 ‘Falchion'
The M2 Falchion has a secondary function that emits a short-range but powerful blast of air that can stun enemies. Use it 30 times to unlock this trophy.
Highly Volatile
Detonate 10 powder kegs
Again, in Chapter 3, The Puppet Queen checkpoint, there are three powder kegs you can detonate. They're located in the lower left, on top of the shed in the middle, and near the ledge to the right. They can be spotted easily.
A Knight No More
Complete the game (any difficulty)