One of the things that I've seen DDL triggers used for is a sanity check on dropped tables... It's one the more popular examples of DDL triggers I've seen in the MS documentation...
CREATE TRIGGER no_drop
PRINT 'Tables cannot be dropped!'
The above will keep everyone from dropping tables. You'd need to modify it to allow only certain users to drop the table, and/or just disable it when you need to drop something and then re-enable it when you are done...
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