Multibanco ATMs are widespread (look for the MB logo). Not all small, family-run shops, restaurants and guesthouses accept credit cards – if in doubt, ask.
Bars Not expected unless table service is provided, then loose change will suffice.
Hotels One euro per bag is standard; gratuity for cleaning staff is at your discretion.
Restaurants For decent service 10%, though many Portuguese round up to the nearest Euro or two if paying by cash.
Snack bars It's courteous to leave a bit of spare change.
Taxis Not expected, but it's polite to round up to the nearest euro.