You can be more creative with Photoshop when you begin to add photos into photos, creating layers of images and achieving a collage effects. You can edit each layer in a variety of ways, including making the added photos transparent. Cutting objects from one photo and placing them in another adds a creative twist to your composition, giving the object a new environment.
Open a photo file in Photoshop and adjust the DPI (dots per inch) to match the output of the artwork; 72 DPI is typical for websites, and 300 DPI is used for a quality print.
Open a second photo file and adjust the DPI to match the first photo. Use the "Marquee" tool to highlight the whole photo or the section of the photo you want to place into the original file.
Copy the highlighted photo or photo section and then go back to the original image.
Paste the secondary photo file in the original file. The pasted photo file will become a new layer that can be manipulated, moved, resized or made transparent.
Using the drop-down menu “File,” select “Place” to insert a another photo into the work surface. It will become another layer that can be manipulated.
If you want a feathered edge on the placed photo, add the number of pixels from the edge you want feathered in the menu box when you use the "Marquee" tool. This option appears when you select the "Marquee" tool.