1. Learn to anticipate that momentum moment – As you look at your sermon in outline form, or the manuscript, whichever approach you take, you should be able to spot where the sermon could start to feel sluggish. It could be a heavy section of explanation, or a sequence of interconnected thoughts, or the second of two similar points. Or it could be that you tend to lose momentum as you move through your last point toward the conclusion. Knowing yourself and knowing your preaching will increasingly help you to anticipate where a sermon may start to drag.
2. Learn to listen as you are preaching – As you are delivering your message, learn to listen to yourself and your listeners. Are you starting to bore yourself? Do something about it. Are they starting to shuffle around, glaze over, look at their watches, or cough? Do something about it. New preachers may deliver in a state of panic and sheer focus, but if you have experience with public speaking you should be able to prayerfully be aware of yourself and your listeners.
Don’t just trudge on through a dull phase of a message. Add some energy, break the moment with an illustration, make a humorous (but appropriate) aside, review and build momentum at the next transition … do something that will help.