1. Collectibles
1.1. All Dead Drop Locations
1.2. All Blacklist Laptop Locations
1.3. All HVT Locations

2. Story-Related
2.1. Hostages Secured (Transit Yards)

3. Miscellaneous
3.1. Distraction Tactician – Call an enemy, then take them down undetected
3.2. Tri-Rotor Functionality – Disable a security device using the Tri-Rotor
3.3. Hostile Shield Secured – Take down a Shielded Infantryman and take his shield
3.4. Evidence Concealed – Hide 5 bodies in containers
3.5. Mission Footprint Zero – Complete a single player mission without being detected
3.6. Enhanced Lethality Demonstrated – Mark & Execute 6 enemies in 14 seconds

Intel Acquired
Collect 24 Dead Drop flash drives
There are a total of 24 Dead Drop flash drives in Splinter Cell Blacklist. Finding all of them will earn you the “Intel Acquired” trophy / achievement and give you extra money. Almost every mission has a Dead Drop (but there’s never more than 1 per mission). To see the collectibles more easily you can buy the Command & Control upgrade for your airplane. It will highlight collectibles when you get close to them.

When selecting a mission you can see exactly which collectibles you have found in it and which you are still missing. When talking to Briggs on the airplane you can see the total progress.

Data Security
Hack 23 Blacklist Laptops
There are a total of 23 Laptop Collectibles in Splinter Cell Blacklist. Finding all of them will earn you the “Data Security” trophy / achievement and give you extra money. You need to reach the laptops undetected or the enemies will destroy them. There is never more than 1 laptop per mission. Some missions don’t have one at all. To see them more easily you can buy the Command & Control upgrade for your airplane. It will highlight collectibles when you get close to them.

When selecting a mission you can see exactly which collectibles you have found in it and which you are still missing. When talking to Briggs on the airplane you can see the total progress.

HVTs Secured
Capture 20 High Value Targets
There are a total of 20 High Value Targets (HVTs) in Splinter Cell Blacklist. Capturing all of them will earn you the “HVTs Secured” trophy or achievement. It will also give you money which can be used to buy new equipment. After finding and capturing such an HVT you usually need to proceed to the next area or checkpoint to make it count. There will be a little pop-up in the top right corner when you do so. The HVTs move around a little, so their locations can be slightly different sometimes (but they are always in the same area). There is never more than one HVT per mission. Some missions don’t have one at all. When selecting a mission you can see exactly which collectibles you have found in it and which you are still missing. When talking to Briggs on the airplane you can see the total progress.

HVTs are marked different than other enemies on your mini-map. They have a bigger red symbol. You might also want to buy the Command & Control upgrade for your airplane. It will make it easier to identify HVTs and when you get close enough they will be highlighted.

To capture an HVT you must use non-lethal means. Knock them out or use your Stun Gun.

Hostages Secured
Save the hostages in the Transit Yards
Mission: Transit Yards
This can be done at the very end of the Transit Yards mission. That’s the 7th main mission. After defusing all bombs you will be in a train with some enemies and civilians. Once you reach the end of the train, two enemies will take hostages and use them as human shields. If you get to close or start shooting around they will kill the hostages.
To save them you should throw sleeping gas. You can buy sleeping gas on your airplane (headquarters) at any time. Alternatively, you could also mark the enemies and use your execution ability to kill them immediately.

Distraction Tactician
Call an enemy over, then take them down undetected when they investigate
Mission: Private Estate
This can be done pretty much everywhere, but the Private Estate mission (4th main mission) is a good place to do this and has some enemies in the very beginning. Go search for a guard and hide behind an object nearby. Now press the Select-Button (PS3) / Back-Button (X360) to make some noise and lure the guard to you. When the guard gets closer you need to press Square (PS3) / X (X360) to take him out.

Tri-Rotor Functionality
Disable a security device using the Tri-Rotor
Mission: Special Missions HQ
This can be done in the very beginning of “Special Missions HQ”. Right after this mission starts you can see some surveillance cameras. Hide behind a wall and release your Tri-Rotor drone. Steer it to the camera and press Square (PS3) / X (X360) to shoot a sticky shocker dart. This will destroy the camera and the trophy / achievement will pop soon after.

If you haven’t already bought the drone you need to purchase it on your airplane (headquarters). It costs $72,000. Upgrading it is not required.

Hostile Shield Secured
Take down a Shielded Infantryman hand to hand and take his shield
Mission: Special Missions HQ
You will encounter an enemy with a shield at the end of “Special Missions HQ”. You really can’t miss this. A short cutscene will begin to play when you enter the room. Take out the other enemies and let the Infantryman get closer to you. Shoot his shield until he breaks down. Now you have a couple of seconds to get behind him and take him out with hand to hand combat. Press Square (PS3) / X (X360) to do so. Now pick up his shield and the trophy / achievement should pop.

Evidence Concealed
Hide 5 bodies in containers
Mission: Safehouse
When you kill the first enemies in the “Safehouse” mission, you will be in an alley. There are a total of 6 enemies and 5 containers in this place. One container in the alley and four in the building you need to enter. Take out all of the enemies and throw one in each container. The containers are blue-colored. You need to pick the dead bodies up and then press Circle (PS3) / B (X360) to hide them.

Special thanks to BiggD from xbox360achievements.org for finding this perfect location and sharing it with me!

Mission Footprint Zero
Complete a single player mission without being detected during gameplay
Mission: Safehouse
“Safehouse” is the first main mission after the prologue. It’s one of the easiest and shortest missions. When attempting this trophy / achievement, the enemies may never shoot at you or ring an alarm. Their “attention meter” (the half circle that fills up when they see you) may never turn red! If it turns red you have been detected and need to restart from the last checkpoint. If the half circle turns all white, you are still good to go. As long as you kill them quick enough before it turns red it’s all fine.

You should be doing this on Rookie difficulty. The enemies won’t spot you that easily. You can replay all missions at any point of the game (even after beating the story) and keep the equipment you have purchased in the meantime. This can be a huge help and make things considerably easier.

Enhanced Lethality Demonstrated
Using Mark & Execute, take down 6 enemies in under 14 seconds
Mission: Insurgent Stronghold
A few minutes after the “Insurgent Stronghold” mission starts you will have to go under a wooden bridge. At this point you must already have a full execution meter. While you are under that bridge, shoot it until the guards hear you. This will make them group up and that’s exactly what you need. They have to be as close as possible together. There’s also a checkpoint right there, so you can retry anytime.
When you reach the other side of the bridge you need to make your way through the building, go up the stairs, and wait at the window outside. Wait until the two guards inside the house and one from the outside are in your line of fire, mark them with R2 (PS3) / RB (X360) and use your execution to kill three enemies at once. Before shooting them, you should also throw some flashbangs (so the other enemies won’t attack you). Now quickly kill an enemy with hand to hand combat to fill up your execution meter and mark & execute the remaining 3 enemies.
Also keep in mind that you have to play on Rookie difficulty and need to equip the strongest armor in the game. Otherwise, the enemies will kill you. Activate the Sonar vision of your goggles to spot enemies quickly.