This is one lots of preachers, lectors, and even musicians have trouble with: practice. Ever since we were kids, perhaps. But the advice here is not only sound, but it really helps:
 After revising the homily; practice it. Repeat it several times to become familiar with what has to be said and how to say it. Practice it aloud and ask if that is really “me” speaking. Does it sound natural, or have I introduced words and phrases that sounded good when I jotted them down but are not suited to oral communication? It may be helpful to preach the homily to a friend or co-worker or to use an audio/video tape recorder. Can I say to that person without embarrassment what I intend to say to the congregation? Do I really believe what I am saying, or have I hidden behind some conventional expression of piety or theology that I would probably not use in any other situation?
The suggestion of making an audio recording for a practice is a good, but potentially devastating one. These days, with the advent of cheap, plentiful video recording technology, one can also record one’s mannerisms as well as audio. Maybe it’s not an everyday event, but at minimum a preacher should be recording Sunday homilies to see how the visuals come across.
As for the “conventional” expressions, keep in mind this term applies pretty much to any philosophical approach: traditional, modern, neo-trad, or whatever. Most parishes are not filled with parishioners up on the latest lingo from the net, or from books, or wherever.
The bishops also mention a principle rather forgotten by the current translators of the Roman Rite: the language of oral presentation must, by necessity, be different from the written form.
(All texts from Fulfilled in Your Hearing are copyright © 1982 USCCB. All rights reserved. Used with permission.)