How to make a smooth transition into a new iPhone?

I plan on getting the new iPhone. How do I make sure all my apps and everything transfer smoothly. Thanks!

Added (1). From my iphone 4 to the new one.

You're talking about transferring apps to iphone osx? Not gonna work

If you mean upgrading you existing iphone, not a problem, just back up in itunes and when you sign in to the app store they usually download all the apps you had on your old iphone, if not then you can't transfer apps from one os to another, try writing a list down and downloading the apps off of that list.

Easy, connect to itunes and backup first, then connect new phone and choose option to load from backup. Just to be safe also turn on icloud and backup there also one time. You can go to http://www.icloud.com/...icloud.com and sign on there, and it will show you the data you have backed up.

You can head to the Apple Store where they will do a personal setup. You can also back up your iPhone's data to your computer and iCloud through iTunes, and once you obtain your new iPhone that backup will seamlessly transfer your information to your new iPhone.