How to Make a Recently Added Playlist on iPhone
Apple's iPhone smartphone works in conjunction with the iTunes media management application, allowing you to manage the songs stored on your device. ITunes has a "smart playlist" feature that lets you automatically create playlists that match certain criteria. You can set a playlist so that it only contains songs you recently added to your iTunes library. You can then have iTunes generate your playlist and place it on your iPhone device in a few simple steps.
Double-click the iTunes application icon to launch the application. Click the "File" tab and select "New Smart Playlist..." from the File menu.
Click the criteria drop-down menu that is the furthest to the left and select "Date Added" from the list of options. Click the second criteria drop-down menu and select "is in the last" from the list of options. Type the number of days that you want to include in the smart playlist in the space provided. All of the music that was added to iTunes in the specified number of days will be added to the playlist.
Click the "OK" button to create the smart playlist. Type a name for the playlist in the space provided under the "Playlists" heading in the iTunes application window.
Connect the iPhone to the computer via the USB connection cable that came with the device. Click the playlist that you created in Step 3 and drag the playlist onto the iPhone, listed under the "Devices" heading. Allow several minutes for the playlist to be added to the iPhone. Once the playlist has been added, click the "Eject" button next to the iPhone in iTunes and disconnect the device from the computer.