I am currently working on a big audio editing project. I have found this workflow works good for me:
1. Listen to the clip, noting areas where this is nothing but noise.
2. Highlight an area that contains nothing but noise.
3. Open the noise removal tool and select Get Noise Profile.
4. Close the tool and select the entire audio clip.
5. Open Noise Removal again. I find it helpful to first remove 6 DB of noise. If the clip was recorded at a very loud level I remove 12 DB of noise. You can always remove more noise later.
6. Listen to the clip again, noting where clicking sound might be. Highlight each clicking sound and press the Delete key. Audacity has a tool that removes clicks, but I have found my method works better.
7. I always set Audacity so that if there is clipping on the track it is highlighted in red. Select the clipped areas and select the Clip Fix effect.
8. Normalize the clip if needed.
9. Export the MP3 file and save it in the location where you keep the files for this project.