Have you been struggling with perspective? You can't seem to get the right angle of this character or your having trouble making this background landscape feel more 3d. Well, let's talk about some basics of perspective to help you understand better.
HORIZON LINES
Horizon lines are basically your eye level. Horizon lines are an imaginary line that separates the sky from the ground. It helps viewers get a since of depth and makes your artwork seem to pop more. Let's use horizon lines to get a perspective of an object.
For example, let's say we had three people on different platforms looking at a cube. They would see the cube in different perspectives. Red would see the bottom of the cube, yellow would see the middle of the cube, and blue would see the top of the cube. But where would the horizon line be?

For red their eyesight is looking up at the cube making the horizon line be below because their eye level is below.
For yellow their eyesight is straight forward at the cube making the horizon line across the center because their eye level is in the center.
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And for blue their eyesight is looking down on the cube making the horizon line be above because their eyelevel is above.
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And for blue their eyesight is looking down on the cube making the horizon line be above because their eyelevel is above.
As artist we are trying to create an image of something by using our eyes to represent it. That's why your eye level could also be called the horizon line. Some people also call this the camera level. Think about it this way, your eyes are like a camera and what you draw is what you see. Using this as a strategy could help you understand horizon lines a lot better.
VANISHING POINTS
Now let's get into this a little deeper and talk about vanishing points. Vanishing points are parallel lines that seem to converge as they recede into the distance on a point on the horizon line. An example would be you looking down a hallway at school or looking down a straight road on a highway. (the example below)
Do understand that all lines that are parallel to each other will converge at the same vanishing point. Knowing this we can look at other examples of vanishing points. Look at all three of these images. All these parallel lines converge into a vanishing point giving the image more depth.
These are just the basics of head on perspectives. There is a lot more to unpack so here is a more detailed YouTube video of horizon lines and vanishing points. In the video he talks about other angles of perspectives and gives you visuals of what that looks like.
CONCLUSION
Perspective is not all that hard unless you have guided lines like vanishing points and you find a horizon line. After a couple of art studies with these techniques it should be super easy to make your artwork come to life.