Granular consent/solicit codes (UK based)

I'd like to know if anyone has found an effective way to record and manage consent preferences on a granular level? At the moment, we use the consent function in RE to manage 6 solicit codes - 3 Yes to post/email/phone and 3 No to post/email phone (Yes and No codes required due to PECR - you can't email without an opt IN, but you can send post unless there's an opt OUT). Technically, GDPR rules mean we must provide granular consent preferences so that people can pick and choose what they want to hear about. But I can't think of an easy way to manage this that won't get really confusing, especially when building queries. Has anyone achieved it?