Here's the step by step process for this artwork. Please look from left to right
Total layers: 190+
(1) Sketch - This is my way of sketching overall idea of the image. It's usually messy but at least I'm getting the idea.
(2) I always start painting the background. I use B&W for values. I used the texture of the wood from cgtextures.com
(3) I colored the background using Overlay and Softlight. Then new layer for the flowers, etc.
(4) Now for the white part, I locked the transparency then started coloring the base.
(5) Adding some details.
(6) More details. Added the light source.
(7) I decided to add flowers at the foreground to make it look like a photography shot.
(8) This is the part where I always change the overall colors by using Channel Mixer and Curves. Look at the Layers window, very bottom section where buttons like Delete Layer, Create New Layer are lined up.
Added some Overlay and Hardlight layers.