Qualifiers

Weed out all those unnecessary qualifiers, described by E.B. White as: "leeches that infest the pond of prose, sucking the blood of words." Some are ludicrous, contradictory and very fatal, while others diminish your ideas. If deleting the qualifier is not enough, find one good, strong word that will do the job, and use it. Adjectives and adverbs are all very well in their place, but if used to bolster a weak sentence or a weak verb, cut them out and find stronger verbs.

Remember that it is far better to show, than it is to tell.

For example:
(poor writing)
The train suddenly picked up speed. Before long it was going very fast, so fast that it swayed dangerously as it sped down the track.

(edited version)
Without warning, the train increased its speed. Passengers, jolted from their morning papers when the carriages rocked wildly from side-to-side, gasped and lunged for hand-holds.

As you can see, the first piece of writing is weak; there is no life in it. The second is better; the reader can see and feel what the characters are experiencing. Words like 'suddenly', 'very', and 'dangerously' are the weak links here so I cut them out. Then, rather than 'tell' the reader what was happening, I used words that would 'show' the action. Stronger verbs, such as jolted, gasped, and lunged, help to create the atmosphere I was aiming for. As you can see, adverbs have their place too; I added 'wildly' to enhance the effect I was trying to achieve but a final edit might see me remove it altogether.

Consider editing as a cleaning chore - you are cleaning out the redundant, and polishing up what remains. If a sentence can stand without a word, cut it out. If the sentence, or the passage does not convey quite what you want to say, add words or sentences, or re-write it all together.

Remove every word that is there just for the effect.

Above all, aim for strong writing by eliminating all those words that weaken it.