In my reading, I came across this quote:
Preaching is an open and public instruction in faith and behavior, whose purpose is the forming of men; it derives from the path of reason and from the fountainhead of the “authorities.” Preaching should be public, because it must be delivered openly. That is why Christ says: “What I say to you in your ear, preach upon the housetops.” For if preaching were hidden, it would be suspect; it would seem to smell of heretical dogmas. The heretics preach secretly in their assemblies, so that they may the more easily deceive others. Preaching should be public because it must be delivered not to one, but to many; if it were given to a single man, it would not be preaching but teaching – for that is where the distinction lies between preaching, teaching, prophecy, and public speaking. Preaching is that instruction which is offered to many, in public, and for their edification. Teaching is that which is given to one or to many to add to their knowledge. Prophecy gives warning of what is to come, through the revelation of future events. Public speaking is the admonishing of the people to maintain the well-being of the community. By means of what is called “preaching” – instruction in matters of faith and behavior – two aspects of theology may be introduced: that which appeals to the reason and deals with the knowledge of spiritual matters, and the ethical, which offers teaching on the living of a good life (Alan of Lille, “The Seventh Rung” in The Company of Preachers, edited by Richard Lischer [Grand Rapids: Eerdmans, 2002], 4-5).
There may be a lot to exegete here. However, I was particularly thinking about the part “Preaching should be public because it must be delivered not to one, but to many.”
I believe one of the ways that you can help your pastor to preach well is actually to show up to church for worship service. In fact, don’t come alone. Bring someone with you. It isn’t that preachers crave to preach in front of thousands, but just that there are actually people to preach to.