Blending two images smoothly

Start by opening an image of a chair.

Insert another image preferably of the similar size and angle.

Click add vector mask button at the bottom of the layer palette.
Select gradient tool. Enable black to white gradient and apply in linear mode.
Select and merge both chair layers. Create a selection of the chair using polygon lasso tool.
Press Ctrl+J to copy paste the selection in a new layer. Select the background layer and fill with a solid color.
Select the chair layer. Duplicate layer. Enable lock transparent pixels from layer palette. Press Ctrl+T. Right click the layer and select distort. Fill it with black color. Adjust nodes to create a perspective shadow.

Reduce the opacity to 50%.