Gears Of War Ultimate Edition - Insane - Act I: Ashes

Learning the timing for active reloads is key for Insane, as is familiarising yourself with a variety of weapons. You can get through most of the game with an Assault Rifle (I generally prefer the Lancer for consistent fire rate), but you'll want to use Grenades fairly well, and get used to the Shotgun and at least one of the Sniper/Kryll Bow (the latter being more important to be honest).

After Dom frees you from prison you're presented with a split choice immediately, go for the prison block for training if you want, but it's more just a tutorial that you don't really need.
I had already collected COG Tag 1 (and 3) when making sure the game ran fine, so I just show the location of these.
The Crimson Omen can be a good guide for blindfire, as you'll generally shoot towards the centre, depending on the spread/arc of the weapon used.
You'll notice some enemies have head armour on, and these will take more of a beating. A Sniper Shot will remove it later, but Grenades/shooting the knees is a better choice if they become exposed until then.
The few encounters for the first act should be fine.
Chapter 1 ends with Marcus and Dom boarding the Raven and narrowly escaping a Corpser.

The intro to chapter 2 shows the improvements to the character models from here and the original.

You'll see the Crimson Omen fairly quickly in Chapter 2, and there's an obvious COG Tag near it. You'll see that the Grenade can be useful for Stunning enemies, even when it isn't accurate enough to kill them.
Soon you'll see an Emergence Hole. If you can toss a Grenade in them you'll close it up and prevent a fight against a few enemies, however sometimes the extra ammo can be helpful. Inside there's a couple more. I manage to close the first one.

Chapter 3 starts with you facing down a Troika, flank it and take out the Grunt manning it, then use it to take out the couple that approach.
Head to the centre of the ring and grab more Grenades. I manage to close off two of the Emergence Holes, which helps quite a bit, but if you have Grenades saved, you can take them all out quickly with good aim. I somehow just about miss the 3rd/4th ones.
The eponymous fork in the road decision doesn't really matter, but the Left path has two Grunts that will funnel down the stairs so it's easier, even if you can't Grenade as well. On the second half flank right and take out the Spotter. You can slowly take out the Grunts on the Troika if their attention is diverted. Worth doing, to be honest. The building is a safer location than the Troika for dealing with the Emergence Hole foes.

Don't underestimate Knock Knock. The Grenadiers can take you out quick (which is why I only show the COG Tag location). Head inside via the right handside and force your way through slowly. Carmine gets sniped and then you have to take out some more emerging grunts. I think in the original you could nab a Longshot here, or maybe it was lower difficulties?
Keep the Gnasher either way, you'll wanr it to down enemies which flank you.
There's a small jumpcut from the end of this Chapter to the beginning of the next, I can't remember why I cut it.
You'll get introducted to (Baird and) the Cole Train here, my favourite character in the series. After that an encounter with Wretches that you'll need to be mobile and good with the Gnasher to come out unscathed. You'll then get practise with the Hammer of Dawn, swap the Gnasher for it. There's more Wretches, but in a more open area, so easier to deal with. Learn how the Hammer of Dawn works, because you'll need it at the end of the Act. The Grenade toss before the COG Tags worked out well.

Wrath has nothing new really. You'll need to flank right to get to the Troika, and then use it on Wretches. There's another skip from a death, but nothing is missed. The end of the act you'll need to be on look out for Nemacysts whilst dealing with Locust forces.
At the end a scene of General RAAM killing Lt. Kim occurs and we get trapped inside.

The final chapter is a boss level.
Be aware of your surroundings and maintain distance. Use small bursts to lure the Berserker and use her to destroy the pillars and door on the way until you're outside, then you can use the Hammer of Dawn and regular weapons (whilst stunned) to kill her.

0:00 - Chapter 1: 14 Years After E-Day
2:00 - COG Tag 1 (Location Shown)
6:35 - COG Tag 2 (Collected)
8:20 - COG Tag 3 (Location Shown)
9:20 - Chapter 2: Trial By Fire
13:43 - COG Tag 4 (Collected)
20:37 - COG Tag 5 (Collected)
21:12 - Chapter 3: Fish In A Barrel
25:25 - COG Tag 6 (Collected)
28:45 - Chapter 4: Fork In The Road
36:26 - Chapter 5: Knock Knock
37:15 - COG Tag 7 (Location Shown)
44:30 - Chapter 6: Hammer
49:00 - COG Tag 8 (Collected)
1:00:10 - COG Tag 9 (Collected)
1:00:58 - Chapter 7: Wrath
1:17:10 - Chapter 8: China Shop
1:19:15 - COG Tag 10 (Collected)
1:21:08 - COG Tag 11 (Collected)
1:22:40 - COG Tag 12 (Collected)