Adding a filter for greeting cards - christmas, easter, father's day etc etc

I have watched countless videos on metaobjects etc thinking it would answer my question but I am struggling to find an answer. I just need to be able to tag my greeting cards ‘christmas’ for eg and for that then to be available in a filter so when someone is viewing the whole range of greeting cards, they can use the filter to only see Christmas cards vs general etc. etc.

Is this easy to achieve and what would be the best way of getting this done?

Thanks a million!