Tilt shift photography is the method of taking a photograph and applying digital image manipulation techniques to make the photograph appear like a miniature model. Not all photographs are conducive to titl-shift techniques. However, it is fairly easy using many image manipulation software programs. Software such as GIMP or Photoshop have historically been good choices.
There is a quick way to make a tilt-shift image. First select an image. The best image is one that is typically taken from a higher perspective. The image’s focus will be in the foreground with a scene behind this. There are likely better words to describe this but consider a good scene that you could imagine constructed as a miniature scene.
Open the image in Photoshop (for this demo). Press Q to enter quick mask mode. Pres G to open the Gradient Tool. Make sure you are using the reflected gradient option for htis tool. Draw a vertical line over the x-axis of the image where your focus will be. Once the mask has been applied press Q to exit the quick mask mode. Select filter -> Blur -Lens Blur and adjust as desired. Select Ok, and Save As… a new file name. Experiment as you wish.