"Luke... you must go to the Dagobah-system..."

Step 1

Ever wanted to create those cool StarWars-ghost sightings? Well, just open up any picture to put the ghost on;

Step 2

I will use Obi-Wan having a conversation with his old master Qui-Gon, now I need to open a picture of Qui-Gon first;

Step 3

Then I need to cut the background out of it with a desired tool...

Step 4

And cut off everything that doesn't fit the image.

You can see it clearly when you lower the opacity;

Step 5

Ok, now you're done right?;

Step 6

Now you can either add a Gradient Map or just duplicate (Ctrl+J) the layer 2 times and make both blue and set the top-layer to overlay;

Step 7

Also add a white-blue outer glow;

Step 8

Now lower the opacity to a decent amount;

Step 9

And finally, if needed, press Ctrl+U to make the image a bit more lighter..