Open in Photoshop the photo you want to put on a new background, as well as the desired background image, which should be approximately the same size and resolution as the photo itself.
Pick a background and a photo so that they had about the same level of brightness, light and color saturation. The fewer operations change colors you will make, the more realistic it will look next collage.
A window will open with the photo you need to cut from the old background. Select tool the quick mask by pressing Q. Take a soft brush with a small diameter and begin to paint a human figure so as to completely encircle the inside of his footprints and not to leave any unpainted area of the figure.
To carefully select fine details, hair, and fingers, select a thinner brush and modify the selection. Once you completely paint over the figure, press Q to exit quick mask mode. You will see that the shaded area has turned into a selection.
Click on a selected shape, right-click and hit Layer via copy to copy the shape on a new layer. Then remove the selection on a separate layer, where you move the shape, copy it (Ctrl+C), go to the window, open the new background and hit Ctrl+V to paste on it a human figure.
At a new duplicate background layer with the human figure (Duplicate layer) and merge the layers. While on the shape layer, hit Ctrl+T to open the tool to change the size and shape - Free Transform. Shift without changing the proportions of the figure, change its size – increase or decrease so that the figure looked in their new surroundings proportionally and reliably.
Place the figure where it will look more successful and profitable. Then check to see how much different colors and the illumination shape with photos and background.
Adjust the brightness and saturation using the Levels and HueSaturation. Change the blending mode of the layers to Soft Light. Then click the menu option Layer the Matting and select Defringe 1 pixel – this will smooth out the unwanted bumps and a bright band around the inserted in the new layer shape.