Some people practice for an upcoming speech by reciting the speech over and over while pacing about a private room in private. They get the content down well using this method. But then they get up to do the speech and discover they have to use a handheld microphone with a long cable coming out of it. This can throw some speechmakers off their game. Some find themselves awkwardly bumping the microphone against their bodies making loud thumping sounds that annoy the audience. Others want to use notes and suddenly find themselves with paper in one hand and a microphone in the other. This makes gesturing extremely difficult.
If you’re going to make a wedding toast, a business presentation, or a public speech of any kind, find out ahead of time if you will be using a microphone. If so, practice with a microphone, or at least some object in your hand so that you get used to holding it while talking and gesturing. Arrive at your speech early and do a sound check. Get as familiar with the microphone as you can before your presentation begins.
The time you invest in practicing with a microphone will pay off in a big way once you are on stage.