Plugin output level
When processing sounds with plugins it can be easy to end up with long plugin chains with levels all over the place.
In some scenarios you can get some great sounding tones this way, however in a lot of cases you may actually be degrading the quality of the source sound or introducing artefacts such as clipping.
When processing make sure you adjust the output level of the plugin so that it matches the bypassed level.
This way you can A/B to hear if the plugin is actually making an improvement rather than just making it louder (which in most cases feels better).
This will help make better decisions and help you understand how your plugins are actually working too.