In my writing groups we have the literary equivalent of a swear box for anybody who uses -ly words without proper caution.  Using more words than you need dilutes the power of your work.  Go for the perfect verb, rather than opt for one that is less than ideal and then have to qualify it with a dreaded adverb.  The boy walked slowly down the road tells the reader much less than the boy dawdled down the road, or the boy trudged down the road.  Become allergic to words like suddenly.  The door opened suddenly is a much slacker phrase than the door burst open - here the impact of the action is captured in the short, quick fire words.