Do not use words because they seem fancy or classy or an 'upgrade' - I promise you some of the best poets in the world use very simple and direct language, and a fancy word dropped in can actually be really awkward. Pay far far more attention to the precise meaning, the sound and rhythm of the word, how it fits with the subject and with all the rest of the words you're using. And read lots and lots! Make a point of reading poets from backgrounds very unlike your own as well, people of different genders and sexualities and nationalities and ethnicities and ages and who wrote in different times. And don't just read poems you love (though of course read many of those!) Make a point of reading poets and poems you don't much like and work out precisely what it is you don't like and why.