Counter-Strike: Global Offensive configuration settings (autoexec.cfg)

Setup (Windows/Linux/macOS)

1. Place the autoexec.cfg file in <path-to-steam>\steamapps\common\Counter-Strike Global Offensive\csgo\cfg\ folder.
2. Launch the game and open the developer console by hitting § or whatever key you have to toggle console.
3. Run the following command: exec autoexec.
4. Restart the game, make modifications to options and autoexec.cfg as you like.

Other Settings

You could also set some useful launch options for CS:GO in steam.

Paste these launch options "+exec autoexec -console -novid -nojoy -tickrate 128 -freq 144 -high" by going to:

Steam -> Steam Library -> Right-Click CSGO -> Properties -> General -> LAUNCH OPTIONS