Let’s get more familiar with 1 point perspective by doing some box drawings. Drawing boxes is by far the best way to learn perspective. Practice this a lot and as often as you can.
Draw the horizon line and in the middle the vanishing point. This is just a reference, so draw lightly.
Draw a square or rectangle. You can actually place it bellow (bellow eye level), above (above eye level) or at the same height as the vanishing point (at eye level). It works just on all three positions.
Now draw a parallel line from each corner to the vanishing point. Each line is parallel to the other three lines.
We’re going to stablish now how long this box is going to be. Draw a line across touching the two parallel lines. This line is parallel to the other horizontal lines including the horizon line.
From where these lines meet draw two lines to the lower parallels. These are the top corners on the far side.
Now it’s time to unite this intersection points (this forms the lower corners on the far side). The rectangle that results from this is effectively the other side of the box. The side we can’t see.
Draw the outer lines of the box applying more pressure so they look darker. We can see the front and top sides of the box.
This is how to draw a box in one point perspective. The box can be as wide tall and long as you want.
Up next are two other examples of boxes in one point perspective, but now with the box in front and above the vanishing point.
In this case where the box is at the same height as the vanishing point (eye level) we are only able to see one side of it.
Up next is an example of the box above the vanishing point (above eye level). Now we see the front and bottom sides.