Notes on Audacity
Display while playing
When finding specific points in time with a large zoom one usually loops the selected region. The default behaviour is for the display to follow the section being played. To prevent this go to Edit -> Preferences -> Tracks and uncheck Update display while playing.
Guide tracks
To optionally add initial silence and/or mute 1 channel, open a new project and import your guide track file. Set the cursor at the beginning of the timeline and go to Generate -> Silence. Enter the desired length and click OK. The silence will be inserted before the sound of the imported file.
Then click on the black downward arrow beside the track name, and click Split Stereo to Mono. A new track will appear. Then pan both tracks to a single channel all the way to the maximum level. Reduce the gain and export.
Signal level/gain of a recorded track
To improve the level/volume of a signal that may have clipping. Create a new project and import the audio track. Select the whole track with a left-click on the corresponding Track Control Panel. Then click on menu Effect and click on effect Limiter.
Keep the default values Soft Limit, Input Gain mono/Left/Input Gain Right = 0.00, Hold = 10 ms, Apply Make-up Gain = No. The parameter to vary is Limit to (dB), a baseline value is -6.00. Click on OK to apply the effect.
Then click on effect Amplify on menu Effect, selecting a value equal to the absolute value of the Limit to (dB) value of previous step.
The signal should display louder but without clipping.