Add a statement of responsibility in the 245 if it is missing from the record but is present on the piece.
Move editors, compilers, etc., from main entry to added entry:
Change the MARC field from 1xx to 7xx.
Change the 245 first indicator to 0.
Change the cutter in the call number as needed to reflect the new main entry.
If there are previous editions and/or volumes, also change the cutters on those as needed. Exception: if there are numerous previously cataloged editions/volumes, use your judgment to decide if it is worth it to re-letter them.
Change form subdivisions in subject headings from $x to $v.
Example: Medicine$xHandbooks, manuals, etc. should be Medicine$vHandbooks, manuals, etc.
Remove $e subfields from 7xx fields for Moody/Jones general book cataloging.
Make other changes as desired to pre-AACR2 records (such as changing ISBD punctuation), but not at the expense of cataloging production.