Keep general phone installation size (incl. IOS) to a minimum I just bought an iPhone 5s and will receive it soon

It only has 16gb of RAM

I will clean install IOS 8 upgrade (this is best, no?)

Will the installation files self-delete after install?

And do you know some good tricks / guides / apps to keep IOS and other install sizes to a minimum? I mean clean up and delete unnecessary files etc.

Thanks
Obviously, the files will auto-delete after installation. iOS has a really good file management system. There are not "tricks/guides/apps" to keep the install sizes to a minimum. This is not Android to clean up and delete unnecessary files, It's done automatically.