It’s good to practice your “podcast voice” ahead of recording. Choose a narration style that won’t clash with the theme of your podcast. Then use your podcast recording software to record yourself and see if you like the way you sound. If not, try a different approach. When you listen back, make sure you are enunciating clearly, and aren’t speaking so fast that listeners won’t be able to follow.
If you have parts of your podcast that are scripted, go over the script ahead of time to build confidence and eliminate “ums” and “uhs.” And just like a singer before a concert, protect your voice leading up to a recording! Avoid screaming, talking too much, alcohol and smoking. If you are recording in the morning, try to wake up at least an hour before so your voice has had time to warm up.
Use a pop filter to eliminate plosives and other irritating sounds that come with using a microphone.
And finally, choose a free podcast software with audio repair tools to fix any vocal issues after the fact.