In this tutorial I am going to show yo how to add borders to an image.
First, open your image in Photoshop.
Next, right click on the background layer in the layers pannels and select Layer from Background option.
Then right click on the layer in the layers panel and select Blending Options.
After that, select Stroke. You have to select the position Inside. Also you can customize the size, colors and opacity.
This is the final result: