Copy these vector shapes from Illustrator and paste them into your master Photoshop document, setting the layer’s blending mode to Screen, at both normal and varying opacities. Play around at this stage – enjoy what you’re doing and allow the piece to build itself. There’s no right or wrong way to do this – you’re in control.
Repeat step 7, building up a composition that suits what you’re trying to achieve. Keep some of the objects at full opacity and some at reduced opacity to give the piece some life and depth. You want to look at adding subtle details to draw the viewer into the guts of the piece when they give it a closer inspection.
Duplicate the background and clip out some vital sections of the woodland to bring them to the front of your image stream. This will give the flow more depth and interaction. It will also tie the front and back of the image together more accutely and help form a more coherent image.
Now you have a clear sense of where your flow is going, draw some more complex vectors in Illustrator and paste them into the Photoshop document, moving them around in the depth of the layers to see where they fit best. Again, this is useful for tying the foreground and background together.