Are there tools that make the job easier? If command-line only tools exist, then can anyone speculate if there is a market for a GUI tool? For example, you can create a relational database by modeling visually. Should the same notion exist for LDAP?
I don't know if there are any tools but it isn't that hard to create them by hand.
If you are using IPlanet LDAP then they had a nice interface for creating and modifying schemas though. :)
I don't know if you would consider that to be by hand otherwise that is one tool to use.
A lot of times you may be copying objects from one tree to another. Or backing them up. In that case, most LDAP tools have some way of exporting as LDIF. Then you can easily modify the files as needed.
Or copy examples to reuse.
I have seen a number of tools that will do tasks and output the results as LDIF, which can be handy, but they are basically point usage tools.
Apache Directory Studio includes an ldif-Editor. It is still a text editor but with syntax highlighting, autocompletion and group collapsing for ldif files: http://directory.apache.org/studio/
I've done some LDIF handling using Perl and the Net::LDAP::LDIF module and it made scripting custom LDAP conversions very easy.
Have you looked at the command-line tool, LDIFDE.exe? Should be on your domain controller.
Business people give me Excel spreadsheets with inconsistent formatting of user and group data and want it loaded right away (then they come back with a new version and tell me they've only added some new users, but some are missing, some data is now invalid, there's a missing column etc.) They want unique passwords assigned, group memberships set up based on department id fields, and so forth.
Then they come back two weeks later and want to know about the differences between that spreadsheet and one from six months ago. Sigh.
I generally just do it all with a few hand-crafted Python scripts.