Have some official with top secret clearance or higher serve as an information ombudsman to both receive requests (C-SPAN style) from the public, and double-check documents where federal agencies claim confidentiality or classification (the onus being on them to opt-in). I'm imagining a low-level cabinet official (maybe the head of a national FOIA library?) who has no influence except the threat of declassification, which can only be overruled by the President.
Why Is This Idea Important?
It will improve the number of declassified documents, produce clear justification when federal authorities restrict access to a document, and more closely link the public's interest with a representative ombudsman accountable to the hundreds of well-intentioned citizens calling in.