User-Specific Properties Files
You can have any number of Properties.username files in your project's Resources directory in-addition-to the default Properties file. These Properties.username files will automatically load based on which user is launching the application. This allows you to have custom logging, email, database, etc configuration settings for each developer.
This capability can also be (ab)used in combinination with the Launch parameter -Duser.name to specify Production vs Staging/Development properties. For example: a launch parameter of -Duser.name=deployment will cause Properties.deployment to be read when the application in launched.
This can be very useful for automatically changing database connection configurations based on whether or not an application is being run in Production or Development.
Development Only Properties File
You can set properties that will only be active if the project is run in Development mode by creating a Properties.dev file. It will be loaded for all users.
Database Connection Properties
While the easiest place to set connection properties is in the EOModel, a better place to put them is in the Properties system, that way you can leverage the flexibility of launch-time loading of Properties so that you set connection info for each user, for development or for deployment.
Model-Specific Connection Properties
Global Connection Properties
These settings will allow you to set the connection properties for all the EOModels in your project.