I've got an ntfs file system in a seperate partition that I store some personal data on. Upon trying the method of individually dictating sort order in a folder on this partition (by modifying the .directory file), I discovered there is no such file there. I tried adding one, but it doesn't seem to have any effect.

Any way to achieve these results on an NTFS file system? --Have sorting order for contents of a folder specific to that folder only

may not be exactly what you want: try settings -> general -> remember properties for each folder

Please note that depending on how the NTFS file system is mounted on the system, KDE may not follow the .directory file in any case as the file system may be seen as "slow" which causes KDE to minimize the number of accesses it makes to it.