File naming

Shared rules

Lowercase
A combination of habit and the use of hyphens has led me to really enjoying the use of lowercase naming.
Followed by: Executable, JavaScript, Website
Hyphens between words
Using a hyphen provided for a solid foundation for my website design skills because it's just easier to read. Before that I was switching between upper and lower case names constantly.
Followed by: Executable, Website
Uppercase first letter of words and the rest lowercase
In the VB world it's a great way to make reading things easier because hyphens and spaces are not permitted. Examples of this would be modThisIsATest and clsId.
Followed by: VB MVC Razor, VB WPF

3rd party image

Resized
It's more sound to keep the original file name when the file is just resized. This way if you, or anyone else, want to find the original, the odds go up significantly.
For a website environment.

Executable

Version prefix/suffix
When including a version number in a file name I prefix the version number with a hyphen or dot, and then sometimes include the build.
For a website environment.
Example:
  1. jse1-1.1.2.19-beta.exe
  2. jse.1.1.2.19.exe

VB MVC Razor

3 letter, lowercase prefix
I've found it easy to name files with this kind of prefix. An example would be clsHelloThere.
Only class files.

VB WPF

3 letter, lowercase prefix
I've found it easy to name files with this kind of prefix. Examples would be winMain and clsDataAlphabet.
All project files except App.config and Application.xaml.

Website

index.html
When working in .html files, or any website file type, always use the default file, that way if you ever switch to another extension, the paths will be valid.
Don't reference the file, use a path only.
JavaScript
I name the file the same as the class name, it just makes things easier.