Not having a second set of eyes for the Director.
An editor can help overview the shots and instinctively know how the edit can come together without needing to be in front of the edit bay. This could save thousands in unnecessary pick up shoots to fix the issue that could have been prevented if the editor was engaged earlier in the production process.
Not having enough crew on set.
Most of the time, money is an issue in production. Cutting crew cost might not be the best solution. Try saving money on location instead of on the crew. Keep in mind the crew is there to help you get the look and feel you are after. If you don’t have enough crew to execute the look, then the overall production will hinder.
Not preserving space on commercial spots.
Lots of times we see all this real estate left and right of frame and think that we need to close the shot up and take out the negative space. By doing this you are limiting the editor to fit necessary graphics on screen which end up making the scene look like an after thought in post.
Not finalizing the script before a shoot.
Not locking the script before a shoot leads to missing coverage, and an unhappy crew that isn’t organized for the next shot. Locking the script and creating a clear shotlist will make your production go much smoother and you will retain a happy crew that will most likely want to work with you in the future.
Not “fixing” it on set rather than relying on fixing it in POST.
All editors have heard this throughout their career. It’s almost always easier to fix it on set than to spend days to fix it in post. Keep this in mind the next shoot you are on set and check with all parties to see if you are able to trouble shoot on location or if it is easier to just fix it in post.