This page, put together by Jim Bednar, summarizes solutions to some problems typically found in student writing, based on experience grading Lisa Kaczmarczyk's Technical Writing course and other CS courses. There are several sections:
Transition words and phrases are what makes such a feat possible. Without good transitions, the reader will end up backtracking repeatedly, which will usually cause your point to be lost.
In practice, making smooth transitions is very difficult. Learning to do it takes a lot of practice at first, and actually making the transitions smooth takes a lot of effort every time you write or revise something. One rule of thumb is that every time you switch topics, you should try to provide a verbal clue that you are doing so, using transitions like "However, ...", "As a result, ...", "For comparison, ", etc. Apart from that, all you can do is read and reread what you write, rewording it until each new item follows easily from those before it.
Thus you should learn to avoid redundancy. When two words will do, there is no need to use twenty. When one sentence will do, there is no need to use ten. Whenever you finish a sentence or paragraph, read over it to see if any words or sentences can be eliminated -- often your point will get much stronger when you do so. Extreme example from a student paper:
"No universal definition of the number of pages in a brief paper exists today. Therefore, in general, the definition of 'brief' could be considered somewhat ambiguous."(Perhaps "The term 'brief' is poorly defined" would suffice.)
Among other benefits, avoiding such informal language will ensure that your meaning is obvious even to those who have not learned the currently popular idioms, such as those for whom English is a second language and those who might read your writing years from now or in another part of the world. Formal writing should be clear to as many people as possible, and its meaning should not depend on the whims of your local dialect of English. It is a permanent and public record of your ideas, and should mean precisely what you have written.
Note especially that most "-ing" words are not verbs -- "The sky being blue" is just a clause, not a sentence. To be a sentence, i.e., something that you can use on its own followed by a period, it would have to be "The sky is blue".
If you do find yourself attacking someone else's work, it is a good idea to put down your paper once you've written it, then go back to it later and read it as if you were the person you are attacking. You will probably notice certain key phrases and terms that would make you angry or defensive, and you can go back and re-word these to make your disagreement more academic and less personal. Remember, the fewer enemies you make, the better.
It is a good idea to read over anything you write, searching for this sort of word. For each instance, first ask yourself "To what, precisely, does this term refer?". For such a reference to make sense, the object, person, or concept must have been explicitly mentioned just prior to your reference. Often you will find that "it" or "they" refers to something vague that was not even discussed explicitly in your paper, in which case you should reword your text entirely.
Even if the item to which you refer is explicitly mentioned in your paper, ask yourself whether there is any chance that the reader might not know to which of several items you might be referring. E.g. for the word "he", were there two or three people being discussed? If so then state the actual name of each; "he" would be ambiguous.
Often an ambiguous "this" or "these" can be disambiguated by adding a noun that specifies precisely the type of object or concept to which you are referring. For instance, "this argument" or "this paper" may be less confusing than simply "this".
If you do not know the difference, avoid using the words altogether. But since the spell-checker takes care of all the other words you may misspell, learning to use these correctly is really not much of a burden, and is crucial for convincing your readers that you are competent. There are many web sites and books available that will explain these and other homonyms.