On the distant land near the mill use the palm brush to create a couple of dark palms. Apply a dark green color overlay effect.
Time to put a pirate in the boat! Open the image “Girl”. Use the Pen Tool to make a selection of the girl (it does not have to be extremely precise as we will resize the girl). Place the pirate girl in the boat as shown below. Use the layer mask to hide the legs so that it looks like she is inside the boat.
I used a couple of layers set to either Overlay or Color Dodge to paint on the pirate girl and make her stand out. Create some subtle outlines with a 1px brush , especially around the sword (it will make it look sharp). After that use a larger soft brush at a very low opacity and paint over the existing highlights to make them stand out even more.
Our scene look pretty good but it lacks dynamism. We can achieve that in this particular scene by adding some nice white splashes. With the splash brushes at various sizes and opacities create some splashes where the creature is emerging from the water and near the front of the boat. Use layers mask to blend them better and clipped Curves Adjustment Layers to make them whiter.
As you can see the devil is in the details. We could go on forever and add all kind of little details but I think that our scene looks good overall. Like a famous person said once a piece of art is not finished when you cannot add more to it but rather when you can’t take elements away from it without make it look incomplete (or something along those lines).
Now it comes my favorite part: adding those nice final effects that will make the scene really stand out. So how do I know what to add? Well, there are a couples of think I almost always do for good looking final effects. I almost always add a lens flare, I paint with white on layers set to overlay to emphasize the main points, I increase the contrast, sometimes I add a vignette, I place good looking textures(nebulas, glitter and special fx) at top of everything and change the blending mode to Color Dodge.
Let’s start with a lens flare. Create a new layer and fill it with black. Go to Filter > Render > Lens Flare and choose the settings shown below. Change the blending mode of the layer to Screen and in the layer mask hide all the bright parts and leave only the subtle lower parts.
The underwater part of our scene looks a bit dull. Let’s fix that by adding some random details. Open the image “Underwater2”, select all and copy/paste in our scene. Change the blending mode of the pasted layer to Overlay. Use the layer mask to hide the part above water. (And don’t forget to convert it to a Smart Object !)
Create a couple of new layer and change their blending modes to Overlay. On one of them use a soft brush to paint with white over the scary fish is and on another use the same brush to paint with a subtle black over the bottom of the scene.
Create a new Hue/Saturation Adjustment Layer and drag the saturation slider to -39. Fill the layer mask with black and paint with white over the bottom of the scene to make the underwater look more natural (as you go deeper there is less light and color).