Here is mine:
1.) Application Definition
=> Explains the mission/goals of the application
2.) Target Audience
=> Who are you building your Application for? (e.g General Public, Students, Parents, Programmers, etc...)
3.) General Requirements Gathering
=> Write down all the requirements of the Application (Layout, Graphics, Content, Features, etc...)
4.) Technical Requirements Gathering
=> All the classes, methods/functions to be used, Plug-ins, etc...
5.) Flowchart / Diagram
=> Flowchart of the whole Application (not really needed, just an option so I always have a map of where i'm headed
6.) Template / Graphics / CSS Creation
=> This is where Photoshop CS, WYSIWYG editor and Notepad is needed
7.) Actual Coding
=> PHP Coding...
8.) Debugging
=> Fix known errors and bugs
9.) Browser Compatibility Testing
=> Test the Application using different browsers and different versions.
10.) Submit the Application
=> Web App is done. Do what has to be done (Search Engine submission, submit to clients, etc...)
Those are my 10 steps to creating a Web Application. What's yours?

