Experience will teach you how to create packages in the right place with the right names. The most effective approach can be to write first with the assumption that refactoring will be often during the first week.
This chapter provides some simple rules to help with the package design process.
[package.name] Package naming
[package.dependency] Dependencies between packages
[package.resuse] Reuse of packages
[package.reuse] Packages designed for re-use
[package.refactor] When to refactoring a package
[package.contents] Deciding package contents