I should state when I say headshots use something that can do it easily like a Marza, Boltok, Longshot, or Shotgun.

Act 1 Baird's Testimony Section 1 Kill the enemies before the declassified mission then only stay back a bit before activating the e-hole. Not too long this takes practice. Having one star is enough to go forward to the e-hole.

Section 2 Same plan stay at the bottom until you kill enough enemies for two stars then go up. Originally I suggested doing one, but two is better.

Section 3 Don't rush to the end in this one too instead kill the Kantus and enemies first. Semi slowly making your way forwards. Getting enough for one star.

Section 4 Free Section

Section 5 Make your way to the right side where you face the turret and stay at the back on the column. Shooting any Cyclops or Maulers you face until one star or more is gained. This is a consistent method I found as the enemies seem to spawn until you move forward.

Section 6 Ideal enemy spawns: Kantus, Theron Guards, and Boomers. Reload checkpoint if you don't get them.

Section 7 Destroy the egg sacks and kill the serapedes before leaving. However in the next section don't kill the serapede immediately as killing it stops the spawns of the wretches/tickers. Kill a few wretches before killing the serapede. If all goes well you should have near 2 stars or 2 stars which is great. Because near the end a grinder will spawn above on a railing. Kill it immediately and that should get you 3 stars or near three stars. If so toss a frag in the e-hole and rush to the end.

Section 8 Free Section

Act 2 Sofia's Testimony Section 1 There's two options either go straight forward or to the left and flank them. Personally I find the left better for safety. Once the locust are killed get on the turret and try to kill a minimum of two reavers on the left side. Then continue as normal trying to get on one of the turrets in the back and kill the rest and reavers.

Section 2 Free Section

Section 3 This one stay back a bit and hope your team mates don't close the e-holes. Getting headshots is almost mandatory. Good RNG is getting two or more stars before the second e-hole in the room. Tossing a frag inside only if you know doing it will ensure three stars or killing the rest will.

Section 4-5 Free Sections

Section 6 Headshots are crucial and getting the intended serapedes and corpser spawns. But there is another with serapedes and boomers/maulers. Former being more ideal because boomers and maulers take a while to kill.

Act 3 Paduk's Testimony Section 1 You must have 2 stars before the gate or it won't be possible to get three stars.

Section 2 Have at least 1 star before going outside of the building.

Section 3 Pick up the Markza near the start by the box except don't kill the kantus. Doing so makes your AI focus on the e-hole and always close it. Then go left for the frags and stay near the frag spawn and get headshots. Theron guards are ideal for three stars, but you can get three stars anyways with drones.

Section 4-7 I consider these free sections.