Tight writing is both effective and enjoyable.
When you read content that gets to the point, that avoids cliches and heavy, dull syntax and grammar -- that almost reads like a good short story or piece by a professional journalist -- that is when you are reading tight writing.
"Keep it short and sweet" should be tattooed on the arm of every content writer.
Use short sentences. Employ action verbs. Avoid the past tense whenever possible.
Make sure you understand the idea or concept you're trying to get across before you write a single word. If you don't really grasp it, you'll never be able to put it to your readers in a succinct manner.
And finally, if your content is much longer than this piece right here -- start editing!