The optimizations are depends on the size of applications, type and other factors but normally we consider following optimizing points i.e.
1. Consider AOT compilation.
2. Consider lazy loading instead of fully bundled app if the app size is more.
3. Keep in mind, your application is bundled and disfeatured.
4. Keep in mind, your application doesn’t have un-necessary import statements.
5. Keep in mind, your application’s 3rd party unused library. If exist and not used, removed from your application.
6. Remove your application dependencies if not required.