A great little quick tip from Youtube user dto911c4s who shows how to use a .BAT file, or an Executable file on OSX or Linux to launch Maya with a unique environment variable just for that particular session.

This is a simple trick to launch Maya with a specific environment variable to run in DX11 mode

This will allow you to set an environmental variable for a one-time “override” in Maya, not particularly every time you launch Maya. So if you want to launch Maya with DX11 mode for a particular project or session, you can use this trick to open Maya in DX11 by setting the Maya environmental variable through the .BAT or Executable for a one-time override.