Require a banner or equivalent consent control before any non-exempt storage or access happens on a user's device. Article 5(3) applies to more than HTTP cookies: the EDPB technical-scope guidance covers operations involving information, terminal equipment, and either storage or gaining access, including tracking pixels, URL tracking, local processing that reports back over a network, and unique identifiers.
Do not narrow the test to personal data. Planet49 and the EDPB technical guidance both treat Article 5(3) as protecting information stored in terminal equipment regardless of whether the information is personal data. The practical question is whether the site, app, email, SDK, tag, or embedded third-party component stores information on the device or instructs the device to send back stored or generated information.