Keep your classes/files short, don't exceed 2000 LOC, divide your code up, make structures clearer. Put every class in a separate file and name the file like the class name (with .cs as extension of course). This convention makes things much easier.
Use .editorconfig file :
This feature work natively on Visual Studio only since Visual Studio 2017, else an plugin is available on https://github.com/editorconfig/editorconfig-visualstudio for Visual Studio 2012, 2013, and 2015.
If .editorconfig is enable, you don't need to modify your Visual Studio setting as mentionned below.
Set Visual Studio where .editorconfig is not enable :
Setup Visual Studio to use 2 spaces as indentation and use Automatic Formatting regularly