One of the greatest compliments a writer can receive, is that his or her writing has a lot of depth.
To have depth as a writer, you must pack as much information into each word, sentence, and paragraph as possible. This means that every word carries an intense weight. A weight that goes beyond the dictionary. Each word represents it's own definition, connects to the writer personally, and connects directly to the piece of work that it's a part of. Each word should carry it's own weight/meaning, plus the weight/meaning of each word prior.
But how do we achieve depth? How do words become heavy?
In my opinion: Simplicity.
Be as simple as you can be - the "you," being the most important part of that sentence... Don't be as simple as possible. Be as simple as you can be.
Every word should be an absolute necessity... If you ever wonder if a word/phrase/sentence is necessary, then it probably isn't necessary. Wonder presents at least some semblance of doubt, and there shouldn't be any doubt.
The more necessary a word is, the more weight it holds. The weight of each word is directly related to the amount of emptiness surrounding that word. Meaning, without fluff and filler, your words will actually gain value. Don't cloud up the true meaning of your statements by adding filler. Keep it simple. Keep shaving off layers until there is no where else to go. You should only be able to write a sentence one way. If not, keep editing, because you haven't written the truest version of what you wanted to say in that sentence.
Plus, surrounding a word with filler and clutter will bring that word closer to filler itself. The boy who cried wolf... (The boy who cried word? No... I digress). Eventually, with enough bullshit, each word loses meaning. So be simple. Write down exactly what is in your brain, and nothing else. That's it. Simple.
Now, being simple is not about writing being easy. Rather, it's about writing being easy to comprehend. The idea of simplicity is on the inferential side of something that is written. Simple writing does not require a simple work ethic or a simple-minded writer. In writing, being simple is being yourself, and you are not simple. Simplicity allows for the easiest access into a writer's mind. Simplicity is the most accurate translation of person to word.
The most simple writing lends itself to the most honest/raw writing, and the most honest/raw writing lends itself to coherence. So, don't make a sentence more than what it is. When your point is across, when your statement is made, your sentence is over. Don't add a single word. Coherence does not come from implanted transition words and phrases. Transition words and phrases are mostly the antithesis of coherence. Truly coherent writing needs no transitions, because the transitions are within the writing itself.
Coherence does not come from any single word or phrase, in fact. Coherence can only be obtained when considering a piece of writing in it's entirety. And while teachers can teach us how to use transition words and phrases, they may not be able to teach us how to write coherently. Because, to write coherently is to think coherently, and to think coherently is merely to think. Simple enough? Cut out the in-between. Remove the bridges. To reach true coherence as a writer, one must minimize the difference between thought and writing. The information should leave your brain as simply as it appeared.
Maximum coherence is the ability to make something into the exact shape of the audience's ear canal. It fits perfectly, with no wiggle room. Your thoughts went right into their brain. Easy. No air on the sides. Perfect. Simple. And for the audience, coherence proves more important than specifically relating to the narrative. There's a gigantic difference between the audience relating to a single thought versus an entire piece of work. There is even a gigantic difference between an audience relating to many separate thoughts as opposed to an entire piece of work. 95% is not 100%. When you reach 100%, something becomes 1. It then becomes a single piece of work. Only then can it even become a candidate for coherence. So, make everything you write one, single piece of work, not a collection of sentences.
So, in closing, being simple is about a lot of things. Honestly, simplicity in writing is not simple. It's mostly an idea. It's a specific way to approach writing. It's a specific brain set up that allows a writer to cut out the unnecessary baggage. Don't consider. Just do. Get to the point. Let it rip.