From how I play (original or mele) I got to make peace every time.
In me1 give data to Tali
ME2 I am always nice with quarian and save those who can be saved. Tali's trial: point out that is a political BS and the Admiralty board will withdraw the charges. Take the compromise option when Tali is trying to shoot Legion. Overwrite the heretics to increase the geth numbers.
ME3. The order of missions is ok as presented, but, defend Legion and aprove every time when it comes about his actions and choices. Also help out in paragon way on the 2 side mission when you can choose to help civilians over increasing defense or collecting scraps.
During your visit to geth server stay and watch every "memory" fragment as some flags might be marked only at the end of the scene and it won't happen if you move away before you see all it is to be seen.
In terms of Reputation, that's how the reputation looks like in my case

and if you prefer numbers:

At the right time, I got both options blue and red dialog pick in order to secure the peace.
I hope that helps