Draw shapes and forms in perspective by envisioning them in three-dimensional space and committing the form to the page with the help of vanishing points, light sources and other visual aids. Perspective drawing takes effort, because it's difficult to convincingly portray 3D on a flat surface.
The vanishing point or points are the fundamental aspects of perspective drawing. These are imaginary points on the horizon toward which all lines appear to converge. Select a vanishing point and mark it on the page. Then, begin drawing the simplest forms, with their lines going toward the vanishing points. Also, make a note of where the horizon is on the page and how it is intended to affect the drawing. Lower horizons are used if the drawing is intended as a birds-eye view. Higher horizons are for viewpoints closer to the ground.
Equally important is the placement of the light source. In most cases, this is likely to be the sun or moon, which illuminates the subject of the drawing from above. Remember that light radiates in all directions equally, so shadows disperse in all directions, with the most intense shadow being directly behind the object from the light source's orientation. Changing the location of the light source can create different effects on the artwork.
When drawing an object in perspective, think of it as a three-dimensional object. Any warping or motion should be reflected accordingly, as well as any guidelines. For example, when drawing a human head, the guidelines marking the locations of the eyes need to be curved. This makes it easier to visualize the head as a solid object rather than a flat image.