Change the blend mode of this layer to multiply, now you'll notice that this smoke image has some sharp edges at the top, we need to get rid of these. We can either use the eraser tool or the layer mask tool, I recommend using a layer mask, but if that’s too complicated for you then just use the eraser tool. Click the layer mask button at the bottom of the layers panel (circle inside a rectangle) then change the foreground color to black then select the brush tool. Choose a soft round brush with a diameter of about 400px and an opacity of about 40% then just brush over the parts of the smoke that you want to hide and you'll get something like in the image below
Next I added a few more splatter brushes behind the skull, I did this in a new layer above the smoke layer, I think I used three different brushes then I changed the opacity of the layer to about 70%.
Now we're going to add a bit of color to the skull, so create a new layer at the very top of the layer stack then fill it with black (go Edit>Fill). Now go Filter>Render>Lens-Flare, hit ok then change the opacity of this layer to 75% then move it so the centre of the lens flare is on the skulls eye.
Now change the blend mode of this layer to screen then if you think the centre of the lens flare is too bright then you can remove it a bit with the eraser tool.
I left the foreground almost totally grayscale so that I could add some bright colors to the background to give a contrast. Create a new layer below the background layer group then change the foreground color to a bright color. Select the line shape tool and change the weight to 20px then holding Shift, make a line at 45°. Repeat this step until you have a few more lines of different colors.
That’s as far as we'll go in this tutorial but there is still a lot more you could do to your image. For example I added some white vector wings in, and a few wee gradients here and there but I'd encourage you to keep on experimenting with it an I hope you learned something new.