The current ILs are good video guides to go by, although some are sloppy. General notes:

• Fastest movement tech is rolling while crouching, but sometimes standing and rolling or just running is useful; this is mostly in short bursts when you're forced to stand and only need to move a few metres to a door/cutscene/vault.
• When killing enemies, it's worth noting that enemies suck at covering, and will usually have a little bit exposed that you can shoot.
• If you get caught in a stealth section, there'll be a cutscene, however, you can pause and restart last checkpoint to skip it, and it won't play if you get caught again.

White's Estate:

• The start is relatively simple. Just follow the commands and skip through text as quick as possible.
• The greenhouse is simple too. Kill every enemy.
• After the camera, roll through the enemies to the door. There's a chance it'll open without you having to open it.
• Roll through the cellar and the house up to the safe.
• After the cutscene showing gaurds entering the house, shoot the chandelier.
• Now kill all the enemies to be able to leave.

Siena:

• Just roll. There are points where you could possibly die, most notably after the van comes in, but it's unlikely.
• In the Mitchell shoot-out, roll left, until you're opposite a shelf and shoot the red gas tank, then roll right and shoot the two other hazards.
• In the QTE part, you can fail but not die at some points. Here's a comparison of an IL of mine and an LP of someone credited in the video, who got two failure-but-not-dead results.

Haitian Docks:

• Crouch and roll to the door
• In this stealth part, if you stay close to the wall you just came from and roll to the ladder, you should get away. Then roll towards the left of the window and stay close to the wall while rolling. A safety strat pre-ladder is to blind-shot the crate, wait a bit, then move.
• When entering the first door, kill the first enemy quickly; the second won't be alarmed.
• Shoot the fan/AC unit, then the camera.
• In the crates-and-barrels area, shoot the enemy on the right as you enter, then turn left and shoot the other enemy.
• Roll straight to where Medrano took Camille and open the door, don't bother with enemies.
• Roll along; then in the open section, you need to kill the sniper, and then the two enemies that come through the gate in order to progress. Recommend shooting the first guy in the barn, then the sparkly box, and the sniper, or you might get mauled.
• After the zipline and the first door, you have to wait for an enemy to open the next door, so try to kill an enemy to help with health (this is a damage-heavy bit). Then roll away.

Opera House:

• Crouch as soon as the first cutscene is over. Don't roll or walk too early otherwise you'll be heard, or the game may crash (it doesn't like showing "Checkpoint" and starting the subdue cutscene at the same time).
• Shoot up at the crate and then move along. Wait behind the wall until the second guard is almost behind the other side, then roll out to the door.
• You can ignore the enemy going up the stairs.
• After the first set of small steps: Risky strat: Stop on the steps, wait for the guard to walk past, making a small opening to crouch-roll behind him and the other guard.
• Safer but not 100% safe strat: Wait before the steps and kill the guard that comes along. Move up the steps slightly and wait until the next guard's head is at the corner of the crate in front, and then kill him. If you didn't wait, a third guard might see the second being killed, failing the mission. Move all the way up and hide behind the left-hand crate for the third guard, and kill him. Then move up the steps and to the ladders.
• Roll around the booth, kill the guard, pick up the ammo from the box and the guard's ammo too, then start the cutscene.
• When sniping, aim to the top, shoot the light so you can see, and try to get a headshot; body-shots are mainly two-shot kills. Then aim down and get the other sniper.
• Switch to another weapon and run back to the first set of ladders. Take out the enemy, then switch back to the sniper and take out an enemy on the top (don't forget the light - this enemy stands right behind it) and one on the bottom.
• Go back to where the first two snipers were. There's a final one on the bottom. Move to the ladder.
• Roll away. It's possible to get through without being killed.
• After the boat cutscene, turn right and shoot the red tank. Roll away - at the stairs, kill the enemy, he basically blocks you off.

Sink Hole:

• This is just a lot of rolling. You might want to kill some enemies to get them out of your way and to stock up on ammo for the heli fight.
• For the heli fight, I'd recommend the AK47 and SAF-5, as they are relatively long-range. Even if the reticle doesn't show red, you can shoot the turret enemies as long as they're in the center of your reticle.
• Roll again. You can kill some of the enemies when getting the explosives for safety and ammo, but you don't have to.
• The sniper part is obvious. Just kill them all.
• For the second heli fight, again use the AK47 and SAF-5 on the turret enemies. The pilot won't take long to kill with either of those weapons as well, in fact, just 6 AK bullets has worked before.

Shanty Town:

• Just roll. No enemies need killing, although there's one that stands by the door before the market area that could hit you/pump you full of lead. He doesn't shoot when you open the door, though, for some reason.

Construction Site:

• Roll around the crane to get to the ladder
• Just roll.
• After the bomb maker kicks a worker down, the metal you need to shoot takes 3 bullets.
• Roll again. You can drop straight down to a button on the left of a platform; mash X as you're dropping.

Science Center:

• After the first guard, head straight to the gate - the guards might be aware of something but not actually shoot at you.
• Roll around to the key, the forklift, the sparkly ladder, the steps (might need to kill an enemy if he blocks you off), and on and on to the vent. Shoot the vent off.
• You can take this whole section safe or risky, but risky strats should still take one or two rooms with caution.
• If you roll along the left of the middle path in one of the rooms, you might be able to get behind an enemy so that he won't hit you. Also, an enemy can open the door for you here.
• It's ideal to kill the enemies before getting on the beam. They'll destroy you when you drop off it.
• Shoot the electrics in the next section and roll on.
• You can get through two of the gates without getting killed, but you'll want to kill the enemies on the third gate. Fourth gate has no enemies.
• You're required to kill the enemies in the next area, and then run around the booth and vault through the window to get to the security cam footage. Then just go to the elevator.
• Switch to the SMG in the elevator if you have it.
• Dimitrios will come out of the far right when you're on the bottom floor, so head to cover in the right and start shooting at him. I haven't found a consistent way to manipulate his AI to a perfect position to kill him, but try hiding near the right-hand pillar.

Casino Royale:

• Kill the first enemy, then just roll through to the balcony.
• You're required to kill the three enemies in the room, as well as the next five enemies (one by the door, two on the left, two on the right) - the last one will have the security card. And also the enemies in the pool section until a cutscene with an enemy running out the door in the far-left corner from the entrance.
• Be careful in the sniper part - you can fall off and die.
• Open the door, and roll away - although take care between the vaulting as there are a handful of enemies.

Barge:

• You can pretty much just roll through most of the first section.
• Don't shoot the cable for the crate like the game tries to guide you towards - it cuts off a shortcut that saves 10 seconds, plus the time the cutscene takes, plus it spawns more enemies. However, you're required to kill all three enemies.
• Roll along, and kill the enemies.
• Turn the valve on the right twice, then turn the valve on the left 3 times.
• Kratt: Kratt Stratt, saves having to shoot the first phase of valves, and the sprinkler in the midsection This is the toughest part, because you get lots of shotgun enemies that can and will destroy you, and Kratt will throw grenades that will destroy you. Just push forward to get him to his final position, and then take cover and be wary of spawning enemies and grenades. You need to wait it out for a valve to glow, then you can shoot, wait a bit, shoot another and so on. Then just shoot him until the cutscene starts.

Eco Hotel:

• There's not really much here. Just roll along.
• If you're feeling lucky:
• Elvis is dumb, like most enemies, as he doesn't completely cover himself. He's easy to kill, although the regular grenades aren't helpful.
• For Greene, shoot the nearest glowing support beam, then shoot the beams either side (if you shot left of him, 1 left beam, 2 right beams, and vice versa). He might float in mid-air if he's reloading, then run to another platform. Just keep shooting beams. Then just shoot at him - make sure to aim for his head for more damage. He'll take a while. There's a chance you might softlock - I don't know what causes it, but the exit door won't let you open it. If you're quick enough, though, you can get through as the enemies open the door.
• Then just roll a lot. Watch out for fiery doors - they will kill you instantly if they explode when you're next to them.
• You can pretty much just roll through the last section. Medrano takes a bit to kill but it's unlikely you'll fail.