Burnt Paper Effect
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3. Burning Effect
First of all you need to select the main paper layer (Hold CTRL and Click the Layer Thumbnail.)

Create a new layer and get the Brush Tool
with a medium-sized, soft brush, brush a few soft spots with a yellowish color (#d99e37)

Again make a new layer and with the brush tool, brush a few soft spots with black (#000000) then you can lower the opacity to what you see is fit (I lowered the opacity to 70%)

Again on a new layer, brush a few bit bigger spots with black.

Set the Layer Mode for that layer to Overlay.

Only one more time, brush around the corners with a black color.

Set the layer mode for that layer to Overlay and change the layer opacity down about 30% if it needs it.

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Photo Effects
Photoshop Basics