Set yourself up for a successful recording. Always record indoors, in a quiet space without background noise.
Test your microphone set up before you begin to be sure you are recording at a proper volume.
Speak clearly and at a reasonable pace- reading from a script can help.
Keep a distance between your microphone and the speaker to avoid feedback or distorted sounds.
If you make a mistake while recording, take a long pause and then clap closely to the microphone before continuing to speak- this will create a visible spike in your waveform to make it easy to find and delete later in the editing process.