The most important thing is to read as much as you can, like I did. It will give you an understanding of what makes good writing and it will enlarge your vocabulary. J. K. Rowling (http://www.brainyquote.com)
Every once in a while I use a word that make some people uncomfortable.
No, not one of those words. Ignoring the fact that I spent almost half a life in the military, it was my misspent youth, nose-deep in books and some years in university, that broadened my vocabulary.
Although my life in military service provided a colorfully-augmented patois of expletives and jargon, it can be a simple use of a word such as “capricious” to annoy someone I am bantering with. Who might have thought that weather, the most innocent of topics one discusses, could inflame emotions.
It is the same penalty-flag my spouse or I may throw when a college-professor friend we know holds a seminar using words we are less familiar with in defining or explaining another unfamiliar word he has used in the seminar.
I am never for a loss of words. However, I have perseverated over those who won’t use dictionary.com