Create a mask out of this layer: Layer ? Add Layer Mask ? Reveal All and choose the Gradient Tool to use it for hiding the visibility of the layer around the waves. It's possible to do this operation by applying very accurate tool's motions.

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Apply the next combination: Layer ? Remove Layer Mask ? Apply. Now we have to open in a new window the picture of an aerial balloon.

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Because it is situated on a white background, we have to mark it out firstly with next command Select ? Color Range? and click on the eyedropper on the same background, just to mark
  
it out:

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Apply the here shown combination: Select ? Inverse (shift+ctrl+i) and Select ? Modify ? Contract (1-3 px). Make a copy of the balloon (ctrl+c) and place it on the top layer, on the window with the processed picture (ctrl+v). Make the corrections on the size and on the turn level, using next option: Image ? Free Transform (ctrl+t).

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Make the corrections on the balloon's colors, just for it not to get out of the common color palette (Selective Color).

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