If you are constantly changing your MonoBehaviour classes to have the curly braces start on a new line then this little trick will save you some time.
Browse to your Unity installation folder and then go to the Editor\Data\Resources\ScriptTemplates folder.
e.g. C:\Program Files\Unity\Editor\Data\Resources\ScriptTemplates
Find the file with NewBehaviourScript in the name. For example:
81-C# Script-NewBehaviourScript.cs.txt
Open it in Notepad++ (to easily overwrite the file, but you can open it in any editor)
Make the modifications you want and save the file. If you can’t save it in the same folder, save it somewhere else and then copy it over.
You can see me do this in a super quick video: