Being an artist, you are expected to be able to draw what you see. And if you are unable to do that, people will consider you to be a crappy artist. Unless of course, you identify yourself as a contemporary artist then anything goes. But that’s another story. To be able to draw accurately, you need to develop a great sense of spacing between edges and relative angles of different elements. In beginner drawing classes, in order to copy exactly, they will make you apply even spaced grid over the image you want to draw, and then have a larger evenly spaced grid lines on your drawing paper. Then block by block, you draw everything inside each block. That is an effective way of matching what you need to draw, but is also an excruciatingly painful process. The thing I took away from that lesson was to never do that again!
You Need to See Correctly!
Most people just see things. An artist need to not only see, but also read the relationship between all the elements involved. The most basic way of measuring what you see is to spot edges or elements that are almost perfectly horizontally or vertically aligned to each other. Just imagine you have the ability to visualize vertical and horizontal lines in your site. That is the first step of seeing relations between elements. Since most elements are rarely aligned perfectly, you will be forced to see the angles between the elements. Measuring the angle is more difficult, but gets easier with practice. That is the key to being able to draw what you see, by reading the spacing and angles accurately.
Once you have the ability to measure with your site, then you are partly developing what people call the artistic eye. You will then notice spacial nuances in everything you see, and you will never be the same. With your artistic eye, a slightly crooked picture frame will irritate you like never before.
Tutorial Video on Drawing What You See
Here is how I measure in order to draw accurately from reference.