To copy contacts and settings between two iPhones of the same version:
1) Plug in the iPhone you wish to copy from and open iTunes.
2) In iTunes, right click the name of the iPhone under the Devices menu and click “Back Up”

3) Plug in the iPhone that you wish to copy contacts/settings to.
4) If the device has not already been synced with iTunes it will give you the option to restore from a previous backup, select which backup you wish to restore to from the drop down list (the most recent will be at the top)

If your device has previously been synced with iTunes you can restore from a backup by right clicking on it under the devices menu and selecting “Restore from Backup…”

5) The phone will then reboot and apply settings (this could take some time, a progress bar is displayed on the phone display) once this is complete, texts, contacts, notes and most settings will be copied to the new phone.

If your phone has been lost/damaged/stolen and you have had to replace it, you can still follow the above steps, from step 3 onwards, as iTunes will have automatically created backups when you previously synced your phone. (Obviously any changes to settings since then will be lost, as will any contacts not backed up to a server, such as exchange)

To copy contacts between any two iPhones:

1) Plug in the iPhone you wish to copy from and open iTunes.
2) On the “Info” tab change the settings so that the contacts sync with your desired account type, then click “Apply” in the bottom right-hand corner.

3) Once iTunes has finished syncing the contacts, plug in the device you wish to add the contacts to and repeat the process, it will then copy across the contacts to your new device.