Once you know your iPhone Wallpaper Size, you can follow this easy tutorial and make your personalized wallpaper from any photo for your iPhone or iPod.  These principles work for any iPhone Wallpaper Size or for any device or gadget, using different image sizes. Though you can make iPhone wallpaper from any photo, choose portrait photos rather than landscape. For creating iPhone wallpaper you can use Photoshop or free image app XnView.

iPhone Wallpaper Size

Here’s a quick chart to make sure you have the proper iPhone Wallpaper Size:
iPhone 4s: 320 x 480
iPhone 5:  320 x 568

Photoshop version

1. Open photo or image for iPhone wallpaper in Photoshop (Ctrl+O).

2. Select Crop tool by pressing C key.

3. Put in Width 320, Height 480, Resolution 72 in Crop tool options.

4. Stretch the corners of Crop tool frame trying include most of image, press Enter.

6. Save for web (Ctrl+Alt+Shift+S) as jpg with Quality 75, check Optimized.
7. Now you have your iPhone wallpaper! Put it to your Photos in iPhone using iTunes and set it as your wallpaper.

XnView version
1. Open photo or image for iPhone wallpaper in XnView.
2. Apply Edit->Set selection ratio->3:2
3. Stretch the corners of Crop frame trying includeу most of image, press Ctrl+Y to crop it.
4. Resize image (Shift+S), put in Width 320, Height 480, Resample – Lanczos.

5. Save your iPhone wallpaper (Ctrl+Shift+S) as jpg with Quality 90, check Optimize Huffman table.

As long as you have the proper iPhone Wallpaper Size, you should be all set