I desaturated the game board and added a layer of clouds using various cloud brushes at 50% opacity.
I cut out all the pictures which needed cutting from the backgrounds, transformed them to size, placed each one on a separate layer, rotated and arranged them till I was happy with the positioning. Adjusted hues, saturation, levels, etc. Added drop shadows to all layers which needed them. Did a bit of dodge and burning where necessary. Erased parts of ladders and snakes using masks so the objects intertwine. Added a few more clouds around the objects. Added a small border. Merged the whole lot, then duplicated the merged layer. Added an oil filter to the top layer and blended it on 40% opacity to give it a slightly dreamy look. Merged end result.

Sorry I did not take screen shots of the progress. I hope the description is enough.