Of course, Tolkien drew the same way as he wrote: with consistency. There is nothing that is there by chance, nor it is ambiguous. Tolkien drew defined shapes with closed contours. As well as every detail in the story has been thought over, every line in the illustrations has been made with a purpose.
It is clear that his favorite subject of drawing were landscapes. All natural forms appealed to him. Whether it was a tree, a flower, a stony path, a spring, or a mountain, he depicted it with equal care.
Tolkien’s artistic skills were certainly limited (for example, he cannot draw people, so they are almost absent from his illustrations), but he employed a handful of smart ticks to achieve impressive effects. He used symmetry (that is drawing the same thing from the left to the right) and a lot of repetition (that is drawing the same object many times). He overlapped several backgrounds to create depth. He drew the nearest objects with many details and vivid colors and the furthest objects with just outlines and faded colors in order to achieve the illusion of aerial perspective.
The final result is a mysterious vista, promising a rich adventure, sometimes it is a bit eerie, but always breathtaking from the first glance.
Word vs Illustration
His son Christopher Tolkien had famously said that no study of his father’s written works can be complete without also looking at his art. Let’s do exactly this—to compare the descriptions of some of the most iconic places from the adventure of Bilbo Begins from the book “The Hobbit” with the Tolkien’s own illustrations of the same places:
The Mountain Path
“...There were many paths that led up into those mountains, and many passes over them. But most of the paths were cheats and deceptions and led nowhere or to bad ends; and most of the passes were infested by evil things and dreadful dangers....”
(The Hobbit, Chapter 4 ‘Over Hill and Under Hill’)
The Thror’s Map
“...There is a dragon marked in red on the Mountain,’ said Balin, ‘but it will be easy enough to find him without that, if ever we arrive there.’ ‘There is one point that you haven’t noticed,’ said the wizard, ‘and that is the secret entrance...”
(The Hobbit, Chapter 1 ‘An Unexpected Party’)
“...Occasionally a slender beam of sun that had the luck to slip in through some opening in the leaves far above, and still more luck in not being caught in the tangled boughs and matted twigs beneath, stabbed down thin and bright before them. But this was seldom, and it soon ceased altogether...”
(The Hobbit, Chapter 8 ‘Flies and Spiders’)
The ElvenKing’s Gate
“...The prisoners were brought before him; and though he looked grimly at them, he told his men to unbind them, for they were ragged and weary.‘Besides they need no ropes in here,’ said he. ‘There is no escape from my magic doors for those who are once brought inside...”
(The Hobbit, Chapter 9 ‘Barrels out of Bond’)
The Huts of the Raftelves
“...The lands opened wide about Bilbo, filled with the waters of the river which broke up and wandered in a hundred winding courses, or halted in marshes and pools dotted with isles on every side; but still a strong water flowed on steadily through the midst. And far away, its dark head in a torn cloud, there loomed the Mountain!...”
(The Hobbit, Chapter 10 ‘A Warm Welcome’)
The Front Gate
“...They did not dare to follow the river much further towards the Gate; but they went on beyond the end of the southern spur, until lying hidden behind a rock they could look out and see the dark cavernous opening in a great cliff-wall between the arms of the Mountain. Out of it the waters of the Running River sprang; and out of it too there came a steam and a dark smoke.
Nothing moved in the waste, save the vapour and the water, and every now and again a black and ominous crow. The only sound was the sound of the stony water, and every now and again the harsh croak of a bird.
(The Hobbit, Chapter 11 ‘On the Doorstep’)