Burned Paper Effect

Create A new file Using These Settings

Then Create rectangle Using Rectangular Marquee Tool

Now you should have something like this:

Fill The rectangle with white colour using paint bucket tool

Now you should have something like this:

Click Q to create mask around the layer

Then Go to Filter -> Brush Strokes -> Spatter

Set the Radius to 20

Smoothness to 10

Click ok

Now you should have something like this:

Then click Q to remove the mask from the layer

Then Go To Select->Modify->Contract

Now you should have something like this:

Then go to Select->Inverse ( Shift+Ctrl+I)

Then click delete button from the keyboard

Okay so now go to blending options and apply these settings in the Inner Shadow area: