How to model relationships between records

For a long while now, we've gotten along fine needing only to model the existence of a relationship between records. Sometimes we've done that via the parent/child nature of "tagging" individual records. We've also recently had some success using Wrike databases to populate a custom field drop down list (e.g. to relate an item type record to an entry in the database).

But now we're needing to model properties of the relationship itself (e.g. criticality, directionality, whatever). It seems like we basically need a record (e.g. a custom item type) that represents the relationship itself with whatever properties we need. And then we'd need to implement a way to indicate the two entities being related. Simply tagging both related entities to the relationship record seems like it won't work since we'll need to be able to know whether, for example, record A depends on record B or vice versa. Also we'll need to support 1:many relationships (e.g. many records depend on record A).

Have any of you come up with an elegant way to model real-world relationships like this in Wrike?