1. Atmospheric Perspective

2. The Illusion of Depth
Creating a sense of depth (3D-ness) in a painting or drawing is not just about using your ruler and making sure all the right lines lead to your vanishing point.
Here are a series of tips and tricks that you’re encouraged to use in your Surrealist Perspective drawing to help enhance its sense of depth.

3. Size Larger objects appear closer to viewers than small ones.
The farther away an object is, the smaller it appears.

4. Overlapping
When one object covers part of a second object, the first ones appears to be closer to the viewer.
This, however, only works when the objects are opaque (not see-through).
And this pair of cute kittens appears closer to us than the pyramids because of overlapping too! (haha)
IE: Due to overlapping, this chicken appears closer to us than the pig, and the pig appears closer to us than the cow!
IE: The smaller pyramids appear closer to us because they overlap the larger ones.

5. Placement
Objects that are placed either high or low in a picture appear to be closer to the viewer than objects placed at eye level.

6. Detail
Objects with clear, sharp edges and visible details appear to be closer to viewers. Objects that have hazy outlines appear farther away.

7. Colour
Brightly coloured objects appear closer to viewers and objects with dull, light colours appear farther away.