This instructable will teach you how to create a double exposure in Adobe Photoshop CC. All you need to complete this tutorial are Adobe Photoshop CC, a portrait photo (a photo of a person's head), and a photo to use as an overlay (i.e. the crayon wax artwork I am using in the examples).
Step 1: Setting Up the Portrait
To start off, import the portrait image into Photoshop. Unlock it by clicking on the lock icon. The image should have an easily identifiable background, such as the gray one in my example photo. This will make it much easier to isolate the person in the photo.
Once it is imported, click on "Add New Adjustment Layer" which is located in the bottom right corner of the window. The icon for it is a half-white circle. Once the option menu opens, click on "Levels..."
A new panel will open up above the layers panel. Drag the triangular markers below the histogram until they line up with the edges of the histogram. This will correct your exposure levels and make sure the image has a correct balance of light and dark.
When you are finished adjusting your levels, select both the levels layer and the image layer, right click on one of them, and select "Merge Layers"
Step 2: Selecting and Masking
Select the "Quick Selection Tool" and select your background. If you make a mistake, hold alt and drag the cursor along the area you want to remove from the selection.
When you have selected the entire background, right click and choose "Select Inverse".
Right click once again and choose "Select and Mask..."
I changed my view to black and white in order to see the selection better, but you can choose whatever view you like best. Open the "Edge Detection" drop down menu, make sure "Smart Radius" is checked, and drag the "Radius" slider until most of the stray hairs are part of the selection.
Set your output to "Layer Mask", then click "OK"
Step 3: Importing Your Overlay
Drag the image you want to overlay onto the photoshop window. Position it how you would like it to appear. If you want to see both layers at the same time, set the opacity of the overlay layer to 50%. Make sure to set it back to 100% when you are finished. Once you have the overlay positioned correctly, click the check mark at the top of the window.
Create a new layer underneath all of the other layers. Make sure white is selected. If black is selected, click on the arrow above the colors to switch them. Make sure your new layer is selected and press "Alt" + "Delete" to fill the bottom layer with white. If you would like to use a different color as your background color, you may.
Right click on the overlay in the layers panel, and select "Rasterize Layer".
Hide the overlay by clicking on the eyeball icon next to the layer image.
Step 4: Prepping the Portrait
Select the portrait layer, click on "New Adjustment Layer" (gray and white circle underneath layer panel) and choose "Black White...".
Select the portrait layer again, click on "New Adjustment Layer" and choose "Brightness/Contrast..."
Select the layer mask (The black and white image to the right of the portrait image in the layers panel). Hold down the "Alt" key on your keyboard, then click and drag the layer mask onto the black and white adjustment layer. If it says "Replace Layer Mask?" click "Yes". Do the same for the brightness/contrast layer.
Step 5: Putting It All Together
Make a copy of the overlay layer by clicking on it in the layers panel and dragging it down onto the new layer icon. Drag the copy down below the portrait layer. Make another copy and drag it to the very top of the layers. Unhide all of the layers.
Hold down "Alt" and drag the layer mask onto all three of the overlay layers.
Select the top layer. Open up the overlay menu (Next to opacity, labeled "Normal") and choose "Color" (2nd from the bottom).
Select the second overlay layer. Open up the overlay menu, and choose "Overlay".
Select the brightness/contrast layer you created before, and adjust the brightness and contrast until you get a double exposure that you like. If you are using an overlay that has color, like me, you can also add a "Hue/Saturation" adjustment layer to the very top, in order to make your colors pop a little more.
Step 6: Exporting
Click on "File", "Export", "Export As..."
Make sure the setting are exactly how you want them and click "Export All..."
Step 7: Be Creative
Experiment! Change things up! These are examples of some double exposures I have done. Don't use layer masks on the overlay, use interesting urban/nature scenes for the overlay, turn the overlay into the background, turn the portrait into a silhouette against a brick background. There are so many different ways to create an amazing and unique double exposure.