Firstly, find a patterned paper that has a large print, such as flowers, leaves, hearts, etc., preferably without too much shading, as that's the enhancing part of this tutorial. I chose this gorgeous autumn leaves paper by Christine Adolph, which features large leaves against a contrasting background. I cut one of the squares from the sheet of 12" x 12" paper. As you can see, the leaf I chose is light in colour compared to the background.
The first step is to outline the leaf with a fine point, permanent black pen. This gives a very definite line between the leaf and the background. Next, choose colours that are darker than, but complimentary to the background. (I used E29, E27 and E25.) Working on the background (not on the leaf) start with the darkest colour and outline the leaf. Working with the next lightest colour, outline again slightly further away from the leaf. The two colours should be touching, and you can bring the outline as far from the leaf as you like. Repeat with the lightest colour, extending even further out from the leaf. With this same pen, blend the three colours using a small circular motion. If you get a very definite line around your pattern you can thin the colour out with the blender pen.
As you can see, there's already a very noticeable difference - the leaf on the right appears to almost pop off the page. This is because of the sharp contrast between the light and dark areas of the pattern. Darker colours appear to recede while lighter colours come forward.
Next, I set to work on the leaf itself. I used E33, E35, and E37 to shade the leaf and add some veins where I thought they would go on a real leaf. Start with the lightest colour and lay down the first shadow. Keep the area you want highlighted - where the light hits fully - free from any ink at this stage, which is how I formed the veins.
Add your two darker colours over the top in smaller areas, darkening where the shadow would be deepest. As you can see, I added the darker shade around the edges of the leaf and beside the veins. These are the places where less light would naturally fall.
Finally, go back over the entire leaf, except the veins, with your lightest colour. Work in small circles to blend the different tones together so you don't end up with obvious changes in colour.
Here's the finished leaf compared to the original. Remember that you can use this technique with almost any patterned paper you might have. It's great for highlighting certain areas of the paper or bringing a focal point forward... have a play and see what you come up with!