For general cases there is a utility called Snapshot which installs a printer driver. Anything printed to this printer is created as a document in the LF repository. This is useful for printing from 3rd party applications directly to a document in Laserfiche.

For the technically savvy there is an interface for automatically sending a document to the repository over a secure HTTP POST. This is good for building an automated bridge to send documents on a schedule or on demand, but requires an HTTP POST activity be available in the product your trying to send from (IE: Great Planes).

https://developer.laserfiche.com/guides/guide_importing-documents.html