There are many things that I as a pastor can and must do to help cultivate good preaching and make it as easy as possible for my listeners to hear what they are saying. I can and must:
Pray: Without prayer preaching will be ineffective at best and harmful at worst.
Prepare: Prayer is not a substitute for sermon preparation.
Rely: See 1 Cor. 2:1-5
Warm: If my heart is cold toward the Lord when I go into the pulpit, I will not be able to bring any warmth to the hearts of my hearers.
Simply: Preaching above people's heads will not make any lasting impression because the message wasn't heard.
Fresh: Because a number of people have been Christians for several decades and have heard multiple messages on many passages of the Bible the preacher needs to bring a fresh perspective (Note: this does not mean the preacher ought to read things into the text that are not there, but to bring our own creativity and personality to each passage preached).
But what can you the listener do?
The most important thing you can do is pray! I once read about a woman who was really struggling with the preaching at her church. She found it dry and unhelpful and, quite frankly, boring. She decided to pray. She prayed for her minister, for his preaching, and for her listening. She prayed that God would give her a deep love for the preaching of His Word and an ability to apply it to her life. And she was astonished at how quickly her minister began to improve as a preacher! He seemed to have changed overnight, and it was all because she began praying for him. I am convinced that many of the problems Christians face in listening to sermons would vanish altogether if they simply spent more time in prayer for their ministers and for the preaching and hearing of the Word.