1) Don't be scared by the grittiness. Embrace the graffiti and street art. Lisbon has a thriving art scene. Street performers and artists are everywhere. There are many cleaner cities in Europe but Lisbon is very safe. Relax and embrace!
2) Lisbon does not represent ALL Portugual culture. There isn't Port wine everywhere...it's a northern thing.
3) Recognize the local pain point. The Golden Visa happened when so many people heard of how cheap it is to live in Portugal. It created an influx of migration, especially of people from Great Britain, Canada, and the US. It drove up prices and drove down salaries. It changed people's lives. Some are suffering. Although they need the influx of travelers to help the economy, many are not supporting their families doing what they want to do. Be grateful that you're being served. The worker may have a highly technical degree in a place where there are no jobs for him/her.
4) It's a city in which people wander. Enjoy wandering but be respectful. If you walk in and take someone's time, buy a little something. Make reservations for dinner. Remember: If it's open between 4-7, it's a tourist spot. Locals have dinner between 8 and 10 pm.
5) Restaurants:
a) Bowls of olives, plates of bread and cheese... the servers bring them to your table before they even ask you what you'd like to eat. If you let them keep those dishes there, you will be charged for them. If you don't want to pay for it, ask the server to not leave it on the table. Then say thank you.
b) Expect to pay €3-5 for a bottle of water at a table. There are no free refills on pop.
c) Your credit card should never leave your possession. Cashiers and waiters will hand you a card reader. The reader will ask if you want to pay in Euros or US Dollars. Always choose Euros. Your bank will convert the amount according to the international banking's daily conversion rates. The store's bank will convert the amount according to their wants and needs. Choose Euro.
d) Tipping is not required, but a 10% tip in cash is appropriate. Don't over tip! 10% is the correct amount. You will look haughty, (which is bad) if you tip 25%.
e) If you put a tip on a credit card, tell the server to add it to the total before they start pressing buttons. If you ask the server to divide the bill, have the amounts figured out, write it down, and show the server that the bill will be fully covered. Hand him a couple Euros in coin for their trouble.
6) Packing tip: hills are real. Tiles are slippery. Be sure to have tennis shoes or sandals with support. White tiles are more slippery than black tiles.
7) There are many street dogs. Watch for dog poop and carry something, like wipes, to clean shoes.
8) Tram 28 does not loop. Locals use the tram. Walking is also possible.
9) Castle of Sao Jorge - book online on your phone. Great place to get views, but you can avoid the tourists and get the same views at the local Miraduoros.
10) The app to use is BOLT not Uber. Give the Bolt driver lots of time to get to you. There's so much traffic.
11) Hang onto your ticket on the train and metros. The ticket gets checked going in, while you're on, and getting off. If an inspector catches you without your ticket, you can get fined 70€.
12) When you're in Sintra, walking up to the castle is hard, but a 45 minute hike on the trail going UP is beautiful. (I think our itinerary has us walking down...I will try to remember to check).
13) Restaurants: Fora in Alfama, Comoba (fast wifi, healthy) , Cafe da Garagem (had great views), Bifanas do Afonso (sweet pork sandwiches, fast food).
14) Alfama survived the earthquake, but has a lot of charm. Lots of hills. Baixa and Chiado are less hilly but are full of tourist traps. Barrio Alto is the neighborhood for partying. It's loud at night. Cais de Sodre has a bit of a party scene, but is close to the river and not hilly.