To get this effect in my pages I squirt water colour paint directly onto the page, I used a large wet brush to spread it onto both pages. When I was happy with it I put a piece of wax paper in between the pages (to prevent sticking)Then continued with the next set of pages.
This is the page with some stuff added. I ripped out pictures from magazines, pages of an old well read book and scrap book paper. I like the torn edges. Cut edges have a different effect, try both. I put gesso on the pictures lightly then went over the edges again. I used paint all over the page to blend it into the background. I set a dye cut onto the page and stencilled paint around it. I saved the cutout for a future project. I used pens and markers to highlight and trace areas. I even used my fingers to apply paint. Get into it, Get Messy!
Here are some backgrounds I started that you can print and use in your art. I love the veiny look from the wax paper.Thank you :)