Create a new file with 1024x768 px and 72 dpi.
Create a new layer and select the Brush Tool (B) with blurred edges, Opacity of 30% to represent the picture shown below. The color in this case is #A2BFE2
Create another new layer (Create new layer) and use on it the same Brush Tool (B) and the color #F7B3D0
Create new layer once again and select one more time the Brush Tool (B) and the color #FDFCE4. This time we need to light up a little the upper corner of the picture:
On the next layer (Create new layer) we'll apply the same Brush Tool (B) and the color #292D3D for darkening out the right lowest corner:
On the next layer we'll apply the Custom Shape Tool (U) and the color #F06EAA to represent several butterflies of different sizes (keeping pressed the SHIFT button).
Find in Internet a picture representing the sky with the clouds:
Insert it on our basic picture, applying the next parameters for the layer: Blending mode-Hard Light
Find in Internet a picture having flowers on it:
Cut them out and insert the elements on the picture. Select Free Transform option to turn over the layer the way presented below:
Apply the next parameters on the layer: Blending mode-Linear Burn
Next we'll select the Custom Shape Tool (U) and the color #89D5ED. We need the instrument to represent several small flowers of different sizes (keeping pressed the Shift button).
Apply the next parameters for the layer: Blending mode-Vivid Light
Find in Internet the picture of a girl:
Cut it out and insert it on the picture:
Using the Pen Tool (P), represent a shape, colored with #89D5ED. The shape may be corrected with the Convert Point Tool. The line's layer must be placed lower than the girl's layer and the flowers' one (on the layers' panel):
Make four copies of the last made layer and choose Free Transform option to place the copies as it is shown below (the copies' colors are shown on the picture). Don't forget to place correctly the layers on the layers' panel:
Next we'll combine in a group all the layers composing the rainbow lines (press Ctrl button and mark out the necessary layers and then keep pressed the left mouse's button to take down the marked layers on Create a new group option). Apply for the group this parameter: Opacity 70%
Create a new layer and choose again the Brush Tool (B) with blurred edges and white color to represent several light patches. This layer should be placed lower than the girl's layer (on the layers' panel).
Download from Internet a set of ready to use brushes for Adobe Photoshop: vector_flowers by Ihea. Create a new layer and apply the mentioned above brushes on it. The brushes' color is white. Place this layer lower than the girl's layer on the layers' panel:
Apply the next parameters for this layer: Blending mode-Soft Light
Find in Internet a picture of the flowers:
Cut out the flowers:
Introduce the cut flowers on our basic picture, making copies of them and using the Free Transform option to change the sizes of the copies:
Press Ctrl button to mark out all the layers containing the recently added flowers and press Ctrl+E (Merge down in a single layer). Press on the next option on the lowest part of the layers' panel: Create new fill or adjustment layer>Curves
Keep pressed next step the Alt button and make a mouse's click between the layers with Curves effect and the combined layer containing the flowers (on the layers' panel) for the effect to be applied only on the flowers' layer:
Choose now the Brush Tool (B), Opacity of 30% and white color on a new layer (Create new layer) on the lowest part of the picture (the brush must have blurred edges):
Find in Internet a picture of butterfly:
Cut out the butterfly and introduce it on our picture. Use the Free Transform option to change the sizes of the butterfly and its incidence to get the same result as it is shown next picture:
Make two copies of the butterfly's layer and apply for the copies the next combination of the buttons: Ctrl+U. We have to change also the color on the copies. We'll make also several corrections on their sizes and on their incidence, selecting previously the Free Transform option:
Finished!
More Tutorials: 
