Wine Tastings & Tours – there are many available, but I went with a Get Your Guide one as I have always found them to be excellent quality and reasonably priced.
If you plan on going to Livraria Lello, the famous bookstore that did not, in fact, inspire anything from Harry Potter be prepared to wait. Queues form as early as 1-2 hours prior to opening. Make sure to buy your tickets online in advance. It’s definitely a cool bookstore (which I enjoy no matter what) and definitely has the HP vibes, despite not having actually been a muse of JK’s, but if you’re short on time in the city there are plenty of great things to do that don’t require standing in line for two hours. There are tours you can do to skip the line and include other Harry Potter related things, though, but they’re a bit pricey.