Most of the time, the shot that looks "right" in camera will not give you the best file for editing and the final result will not be as good. Instead, shoot to protect the highlights even if the photo looks a little underexposed.
If you are just randombly making changes until something looks good, then you are wasting time and not getting the best results. Instead, develop a consistent workflow (or keep reading to learn how you can steal mine).
Lightroom isn't like your computer, you don't need to put everything in separate folders to keep it organized. Instead, use keywords and collections to organize your photos and only one folder per year.
Global adjustments are useful but ignoring the more advanced features like masking will hold you back. Instead, take the time to learn masking, local adjustments, and how to paint with light to enhance your photos.
Too much of anything is bad for you. Overediting your photos will just make them look fake and amateur. Instead, make small changes little by little and watch it build up to a great result. Also, take a break from your photo and come back before publishing it anywhere.
Trying to do everything at once or even making edits in the wrong order can slow you down and hurt your results. Instead, have a good system. Do corrective edits first and then try creative things like color grading.
you can't always trust your screen for precision in editing. If you ignore the histogram you could end up clipping shadows and highlights. Instead, use the histogram to guide your editing and control the contrast and clipping.
Contrast in an image can be good but too much added globally can ruin an image. Instead, use the brush tool and masking to dodge and burn more precisely for much more pleasing results (I teach this in my course).
Editing every image one at a time will take you forever and really stifle your creativity. Instead, use the "Copy/Paste" and "Sync" functions to duplicate your edits over multiple images if they are similar.
If you want to learn how to avoid these and more mistakes, I made a FREE guide for you called "How To Edit Like A Pro In Lightroom" Click below to download it and learn how to get more Lightroom training...