Focus on the foreground.
In Photoshop, open the practice file. Then choose Filter > Neural Filters and select Depth Blur.
Note: You’ll need to download each Neural Filter before using it for the first time. If you’ve already downloaded the Depth Blur filter, simply toggle it on.
Drag to move the focal point in the image preview to the part of the photo that you want to be the focus. Then use the sliders to fine-tune the blur effect.