Pay attention to the origins of your words. English is a confirmed pack-rat language--an enthusiastic, perhaps obsessive, collector and creator of new words. Take, for example, the word "large." Unsatisfied with just the one comparative, English has a whole platoon of others in reserve: immense, vast, capacious, bulky, massive, whopping, humongous.
Like immigrants to a new country, each of these words came from somewhere, and some time. Consulting Dictionary.com reveals that vast came in the mid 16th c. from the Latin vastus. Bulky is a mid-late 17th c. adaptation of bulk, which was born to the late middle English bolke in the early 15th century, which was originally bulki in Old Norse, a word meaning cargo, or ship's hold. Conversely, humongous is a much newer addition to the English melting pot, of American coinage during the 1960s. It is a slang combination of monstrous and huge.
All this is to say that every word we use has a history, and that studying that history is an effective way to enrich your vocabulary and improve your diction. While you're contemplating bulk, for example, you might continue browsing the Old Norse shelf for other colourful contributions such as berserk, cur, or ombudsman. English owes its ability to paint such subtle shades of meaning to this etymological diversity.
Sources for this answer:
Bryson, Bill. Mother Tongue, English and how it got to be that way.
Online Etymology Dictionary
List of English words of Old Norse Origin (Wikipedia article)
Dictionary.com (Not a link, I know. I'm only allowed to post two hyperlinks as a new user.)