Keep sentences shorter and sweeter. A blank line only adds a byte to the article length, so don't be stingy if it will help make your meaning clearer. Pick your words carefully. Writing with precision is as important here as it is in any other kind of discourse. Consider carefully whether what you have written can be misinterpreted, and whether that is something you wish to have happen.
People can only grasp about seven things at once.
There are several variations on any one sentence. A passive, questioning or negative sentence takes longer to read. Remember, most people who will read your posting do not know you. The above applies to humor as well. Take a break before posting something in anger or that might hurt or anger others.