In this method, we create a mirrored border around the design to make it bigger in size and make sure the major part of the design falls within the front portion of the phone case template.

a. Resize the design to fit into the front portion of the phone case design template.

b. Right click on the layer and create a duplicate layer of the design.

c. Move the duplicate layer to the edge. Go to Edit > Transform to move the layer. Hold down shift while dragging the layer to make sure the design is moved in a straight line.

d. Mirror the duplicate image. Right click on the duplicate image, click on Flip Horizontal to mirror the image.

e. Duplicate the mirrored image on the other side.

f. Merge the three layers into one. Select all the three layers, right click and click Merge Layers.

e. Repeat the same process for the merged layer by duplicating it on the top and bottom.

The design file is now ready.