Next we have to download a set of ready to use brushes (http://www.deviantart.com/deviation/35491675/ ?qo=26&q=in%3Aresources%2Fapplications %2Fpsbrushes+sort%3Atime+bubbles) and apply the brushes on the whole picture:

the little mermaid

Make a copy of this layer and blur out the copy (Gaussian Blur).

the little mermaid

the little mermaid

We have to tone the picture, using the Gradient Tool of two colors and change the layer's Blending Mode on Soft Light. Minimize the layer's Opacity till 80%.

the little mermaid

Merge down all the layers: Layer – Merge Visible (shift+ctrl+e) and make a copy of the new layer (ctrl+j). Then make the copy darker and look in contrast, selecting next option: Image – Adjustments – Levels (ctrl+l).

the little mermaid