After scanning in my sketch & refining, roughly coloring, & working out the collage elements in Photoshop, I print out the collage base (I have an archival Epson printer & I use archival paper as well) & begin adding the earliest glazes. Before I collage it to the canvas I want the border colors in so that they don't end up puddling over the edges, & the main figure colors so I know I'm off on the right track before committing it to canvas. So I usually begin with light, thin glazes, again painting/blotting/drying until the basic colors are blocked in.
Then I glue it down with Golden Open Gel.
Please click the image for details. To see all the posts in this process, please click the "Goodly Creature" tab.