An empty phrase can be cut with little or no loss of meaning. Common examples are introductory word groups that apologize or hedge: in my opinion, I think that, it seems that, one must admit that, and so on.
Inflated phrases can be reduced to a word or two without loss of meaning.
You will improve your style if you choose the concise word or phrase over one that is inflated.
Other sources of wordiness include expletive constructions and passive voice.
Choosing the concise word or phrase
Exercises:
Wordy sentences 1
Wordy sentences 2
Wordy sentences 3
Wordy sentences 4