Fallout 4 - Get As Far As You Can With All Factions

It's not as simple as you ask. :)

You don't choose one faction over other three but rather choose which one you'll dispose of first, then which one second.

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First you need to know how to remain "neutral" as long as possible.

1. During Molecular Level main quest, get Railroad's help. If you're already past this point, it's still okay, all you need to do is to brin the tape Network Surveillance to Tinker Tom in Railroad after you used it in Institute (you may steal it from whomever you gave it to if you did).

2. During Battle of Bunker Hill, warn Railroad, kill courser you meet before he reaches Bunker Hill then lie to Father you got ambushed. BoS will still be present in that fight so don't bother warning them too.

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That set?
Faction choosing points:

BoS faction quest: Tactical Thinking
When you receive this one, don't proceed as it's siding with Brotherhood against Railroad.

Railroad faction quest: Precipice of War
It's actually the last point of the quest Underground Undercover where you need to warn Desdemona. Do not go warn her and do not start Precipice of War because at that point BoS will attack Railroad and you have to defend them.

Institute faction quest: Mass Fusion
The game will warn you during this quest where proceeding with it means becoming enemy of Brotherhood so don't proceed. You may warn BoS instead if your plan is to work with Institute.

Minutemen faction quest: Defend the Castle
All three other factions will attack in waves. Some say this still doesn't make them your enemies, dunno.

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Assuming you want to get most of the game before choosing anyone knowing all this the solution is simple.

- Side with Railroad to build teleporter and warn them about Bunker Hill.
- Do all Railroad quests but do not warn Desdemona when it's a task in Undercover Underground quest.
- Do all Minutemen quests possible and stop after finishing Old guns.
- Continue with Instutute quests till the point where game warns you about BoS, don't proceed with it (you may continue it later if you want to finish with institute)
- Do all BoS quests till you receive Tactical Thinking quest

Make a manual save at that point and you can then do any faction from that save.