On periodic basis (minimum 1x/month) clean out files on M: drive (set up calendar reminder). Try to keep the M: drive with a minimum of 1 terabyte of space if possible.
If immediate space is needed, concentrate on rare books/modern library materials which generally contain a large amount of files for a single object
Work on files within Ingested folders
Sort files by date modified, beginning with oldest content
Search for content in Digital Collections to confirm files have been uploaded (double-check number of files against number of files within record as well as confirming obj/acc/bib #s match)
Using Bridge to review files can be more useful than windows given larger thumbnail presentation
Delete files on M: after confirming all files have been uploaded onto Digital Collections site
It may be wise to allow for a month of time to pass before deleting files in M in case there is a need to revisit the original files