In an ideal world, once you've figured out what your readers need to read (gathering and drafting) and what order they need to read it in (organizing), then you can start editing, polishing the sentences, finding exactly the right word, shortening some sentences and lengthening others, eliminating useless repetition, replacing noun phrases with adjectives or verbs, and so on. In an ideal world, editing would be like sanding and varnishing a piece of fine furniture after the construction was complete. If you have to re-glue and re-screw at that point, something has gone terribly wrong. Heaven help you if you have to re-measure once the paint's dry. But writing isn't like carpentry. Most of the time you will need revise a draft multiple times, often reorganizing some parts too, before you are ready to sand and polish. So the following advice is offered under the heading of revision, clearly identifying what a draft is actually saying and differentiating that from what you think you want it to say, the re-writing and unwriting that you need to do when the points you are trying to make are still partially buried in stone, as it were.
What kind of X is this X? When you see a comparative adjective like "better", ask yourself, what kind of "better" (more, superior, rarer, preferred) and "better than what?" Comparative adjectives logically require two items or more, but often we will use implied comparisons, say that something is better.
What kind of X is this X applies to nouns as well. Our minds tend to work from generalizations of personal experiences and so when we write we tend to grab a place-holder word, something more general than what we ultimately need. So, for example, we might write "house" even though we are talking about a townhouse or a condominium or an apartment or, and this is a bit more nuanced, not a house at all but rather a home. So after you've written house down and finished the thought, later in that sitting or a day or more late, go back and ask yourself, what kind of house is this house? Is it actually a dwelling place or am I really talking about a state of mind, a sense of belonging and well being?
A few lines up this screen I wrote "a local example" and then twenty minutes later looked at it again and asked myself, what kind of example is this "example", hence "a local example" became "a local example of drafting," and several days later "a local example of what I mean by drafting." Context may have been enough to convey the thought, but readers shouldn't have to make inferences.
On a shallower level, specificity also means finding words that point to other words and making sure they point clearly. Often it's best to replace the pointing word with the word it points to. So, if you begin a sentence with "this," make sure your readers will know what "this" refers to and seriously consider replacing it with the subject of the previous sentence. Same goes for "it" and the other relative pronouns.
If a statement can be interpreted in different ways, it is ambiguous. Ambiguity can be hard to track down because you know what you mean, your assumptions inform your expectations of meaning. Other assumptions might lead to other interpretations. Remember the tappers and the listeners.
Clarity is the opposite of ambiguity, metaphorically, the same object observed from the same angle in the same light with the same instrument. What does a red apple look like to a color blind person?
To clarify, look for words with multiple meanings, look at the opposite word, look for synonyms, near and far. Identify assumptions, prior knowledge's influence on interpretation, trigger words. shared context and shared attitudes lead to same interpretation but allow different responses. (If the answer is always the same, why ask? If the question is interpreted differently, the answers aren't meaningful)
Try to identify social lenses that influence perception, connotation, and even denotation. The same word might be clear to all but mean different things to different groups. Consider the word "best". Product x is best:
Product x might be best in all these ways but if not, then the word will infuriate those whose criteria it doesn't meet.
Scrutinize abstract words and use only when necessary and not open to interpretation.
However, intentional ambiguity can be useful.
People hear what they want to hear, so an ambiguous statement can make it easier for them to hear what they want without you having to commit or running the risk of saying something they don't want to hear. Writing in empty phrases unintentionally is sloppy thinking. Using empty phrases intentionally to mislead or manipulate is reprehensible unless the audience is in danger and can't be helped to a better understanding by less manipulative means.
Ambiguous is not the same thing as abstract. Abstractions are not objects in the world but ideas people have about how the world works, generalizations about experience and feelings. Abstractions are real even though you can't see or feel them directly. By substituting a concrete representation for an abstraction, you can help people see and feel an idea.
We use abstractions all day long -- love, hate, crime, justice, friendship. We tend to use these words as though they mean the same thing to everyone and the meaning is obvious. We shouldn't. Unless you are using a technical vocabulary -- acceleration means something in physics (change of velocity per unit of time), something else in automotives (increase in speed), something else in education (moving more quickly through a curriculum than one's peers) -- you should make sure you readers know exactly what you mean when you use an abstract concept. Either tell them what you mean by it or give an example or both. If you are using a concept in an unconventional way, make sure you say so. If you give them a concrete representation of the abstraction, make sure it's not just a cliché or a worn out stereotype -- mother and child for devotion borders on the cliché. Big brother and little sister might be more effective, because less expected, but if a reader had a big brother who was a jerk, the image might not work. What you want is familiar enough to be recognizable but not so common as to be boring. You also want to make sure you aren't making assumptions you readers don't share.
One technique for discovering the meaning behind the concept is to look for a scene that depicts it. What does success look like? What does it sound like? What does it feel like? What does it taste like? What does it smell like? If you can't find a real representation of the abstraction, maybe you don't yet fully understand it.
A strong writer in full control of her work can switch concrete for abstract and abstract for concrete at will and does so in order to guide her readers to the places she needs them to be. Notice I wrote "places" rather than "ideas." "Places" are abstract, but not as abstract as "ideas."