A style guide for keeping your Unity projects tidy and organized. Compiled from several best practices resources (see the resources section at the end of the document).

This style guide now includes a Unity project template with minimal setup according to this guide and the new .NET4.0 scripting runtime version and Api compatibility activated.

• Never use Spaces in names.
• Use PascalCase for custom file- and folder names, like this: ComplicatedVerySpecificObject. Do not use spaces, underscores, or hyphens, with one exception (see Naming Different Aspects of the Same Thing).
• Keep the most specific descriptor on the left: DarkVampire, not VampireDark; PauseButton, not ButtonPaused.
• Some names form a sequence. Use numbers in these names, for example, PathNode0, PathNode1. Always start with 0, not 1.
• Do not use numbers for things that don’t form a sequence. For example, Bird0, Bird1,Bird2 should be Flamingo, Eagle, Swallow.
• Prefix temporary objects with a double underscore __Player_Backup.

Use underscores between the core name, and the thing that describes the “aspect”. For instance:

• GUI buttons states EnterButton_Active, EnterButton_Inactive
• Textures DarkVampire_Diffuse, DarkVampire_Normalmap
• Skybox JungleSky_Top, JungleSky_North
• LOD Groups DarkVampire_LOD0, DarkVampire_LOD1

Do not use this convention just to distinguish between different types of items, for instance Rock_Small, Rock_Large should be SmallRock, LargeRock.

• Prefab everything.
  • To modify an asset from the store, drag it into the hierarchy and create a prefab inside _Project.
• Use the Project tab's search functionality:
  • Search by Type in the upper right.
  • Restrict results to selected folder only (recursively): Click on Search and selecting the desired folder from the drop-down (operation mode will be remembered).
• Save searches as context sensitive filters (two colum layout):
  • Click on the star in the top right to save a search. The filter will apply to any selected folder, for example:
    • Only scripts in selected (and sub-folders)
    • Only prefabs in selected (and sub-folders)
    • Only animations in selected (and sub-folders)
• Pin folders by dragging them to Favorites.
• Don’t disassemble context-specific assets. For instance, leave the folder structure of downloaded assets intact.
• Use Tags to mark imported 3rdParty assets:
  • Select an item in the project browser and assign a tag in the bottom right of the inspector.
    • For entire packs, mark the top folder of the asset pack.
    • Assets that come as individual files can be marked directly.

Assets
    __NoVersionControl      // Container for temporary stuff, not under version control. More clear???
    _Project                // All custom files.               
        Characters
            Enemy           // Can have sub-folders or not (see "Save searches as context sensitive filters).       
            Player
            ...
        Environment
            Trees
            ...
        Props
            Weapons
            ...
        Managers
        Scenes
        TestScripts
        UI
        Vehicles
    Plugins                 // Reserved folder.
    Standard Assets         // Reserved folder for Unity standard assets.

Prefab everything!

Main
Debug
Managers 
Cameras
Lights
UI
   Canvas
      HUD
      PauseMenu
      ...
World
   Terrain
   Props
   Structures
   ...
Gameplay
   Actors
   Items
   ...
_DynamicObjects     // Parent for all objects instantiated at runtime.

• Use camelCase for fields and variables.

  Example:

  private RigidBody rigidBody;
  
  private int length; 

References:

• https://www.gamasutra.com/blogs/HermanTulleken/20160812/279100/50_Tips_and_Best_Practices_for_Unity_2016_Edition.php

• http://developers.nravo.com/mastering-unity-project-folder-structure-level-2-assets-organization/

• https://docs.microsoft.com/en-us/dotnet/standard/design-guidelines/naming-guidelines

• https://docs.microsoft.com/en-us/dotnet/csharp/tour-of-csharp/