How to increase depth in a doodle drawing
When drawing a whimsical drawing or doodle, there are a few things you can do to make the entire design look a little bit more 3-dimensional:
1) Add drop shadow Drop shadow is the easiest way to create dimensionality of an item right away. Essentially, it simulates the shadow that is cast down from the object.
2) Object Shading This is the second easiest way to give dimensionality to a surface. Thinking of the entire object, shade or color the EDGES darker as to give a rounded effect.
3) Highlight shaded object To increase the shininess of a surface, add a white highlight (if you are coloring with pencil, then you can use a dab of acrylic paint or even leave some highlight spots uncolored.
4) Overlapping objects Whenever possible, try to overlap objects so that they appear in front of others, covering the ones in the back only partially. If you add the drop shadow on the objects that are in front, these two effects will greatly enhance the dimensional feeling of the picture.
5) Warm colors advance, cool colors recceed If you plan to color your doodle drawing, then use mostly warm colors (red, orange, pink, yellow) on the objects you want to stand out; use mostly cool colors (green, blue, purple) on objects which you want to stay in the background or behind others.