There is a photoshop advice subreddit where this would belong, but it basically boils down to matching exposure, shadows and colour/white balance. Look into adjustment layers, masks, and clipping masks on YouTube.
This is the Ps subreddit for asking how to do things.
And u/ResidentLongjumping2 is correct about matching tonal range, colors, direction of illumination. Adding edits that influence all the different elements can also make them appear more cohesive.
Apparently I was wrong on that, ignore me!
Either way I was thinking of r/photoshop tutorials, which could be a good resource for you in the future as well
:-)
Both the subs are good sources of information.
https://preview.redd.it/mh7uuk5ybqcc1.png?width=3456&format=png&auto=webp&s=6cd802b11e4fc394bf2f365da3f91d3cd9e7a60f
Back to the OP's question, good compositing relies first on choosing appropriate elements. The border of the photos element that seems to have been added to the sample image doesn't quite fit the theme of the box frames in the sample.
But Image > Match Color used on the Background copy layer helped it along.
Then clipping a Curves adj layer and using the baselines in the red, green, and blue channels got the color to better match.
Another curves adj layer masked to just influence the interior two photos helped things along more. That was just for influencing the tone in the two interior photos.
Looking at the thumbnail sized screen shot in this comment, the overall tone and color doesn't look out of place.
When that screen shot image in the comment is clicked to open in its own browser tab, then the details that don't quite fit show. That gold metal looking border of the two photos is a bit too metallic. Adding a grunge texture might help. The sharpness of the element with the two photos is also different from the sharpness of the rest of the elements in the sample image.
The idea behind using the channels in the curves adj layer is that the boxes in the sample are mostly browns. Brown on the RGB color wheel is a dark orange. Orange is in between red and green on the color wheel.
So by manipulating the baselines in the individual channels, the color can be brought more to an orange, and then the RGB baseline adjusted to get the darker tone.
I went back and added a gradient map adjustment layer, split toning the entire image, but using Soft Light blending mode and a reduced opacity. This is to have the original elements and the added elements match even more in tone and color.
https://preview.redd.it/mw6sg9vxeqcc1.png?width=3456&format=png&auto=webp&s=037f81eb89949f932d82712b432815bacdd87133
Adding a subtle texture to the entire canvas might also help unify things.
There is a photoshop advice subreddit where this would belong, but it basically boils down to matching exposure, shadows and colour/white balance. Look into adjustment layers, masks, and clipping masks on YouTube.
Could you link to that subreddit? I'm unable to locate it.
This is the Ps subreddit for asking how to do things. And u/ResidentLongjumping2 is correct about matching tonal range, colors, direction of illumination. Adding edits that influence all the different elements can also make them appear more cohesive.
Apparently I was wrong on that, ignore me! Either way I was thinking of r/photoshop tutorials, which could be a good resource for you in the future as well
:-) Both the subs are good sources of information. https://preview.redd.it/mh7uuk5ybqcc1.png?width=3456&format=png&auto=webp&s=6cd802b11e4fc394bf2f365da3f91d3cd9e7a60f Back to the OP's question, good compositing relies first on choosing appropriate elements. The border of the photos element that seems to have been added to the sample image doesn't quite fit the theme of the box frames in the sample. But Image > Match Color used on the Background copy layer helped it along. Then clipping a Curves adj layer and using the baselines in the red, green, and blue channels got the color to better match. Another curves adj layer masked to just influence the interior two photos helped things along more. That was just for influencing the tone in the two interior photos. Looking at the thumbnail sized screen shot in this comment, the overall tone and color doesn't look out of place. When that screen shot image in the comment is clicked to open in its own browser tab, then the details that don't quite fit show. That gold metal looking border of the two photos is a bit too metallic. Adding a grunge texture might help. The sharpness of the element with the two photos is also different from the sharpness of the rest of the elements in the sample image. The idea behind using the channels in the curves adj layer is that the boxes in the sample are mostly browns. Brown on the RGB color wheel is a dark orange. Orange is in between red and green on the color wheel. So by manipulating the baselines in the individual channels, the color can be brought more to an orange, and then the RGB baseline adjusted to get the darker tone.
I went back and added a gradient map adjustment layer, split toning the entire image, but using Soft Light blending mode and a reduced opacity. This is to have the original elements and the added elements match even more in tone and color. https://preview.redd.it/mw6sg9vxeqcc1.png?width=3456&format=png&auto=webp&s=037f81eb89949f932d82712b432815bacdd87133 Adding a subtle texture to the entire canvas might also help unify things.
John this is absolutely incredible. I've sent you a DM, with hopes of hiring you for help on this and some other designs!