Many cities and towns in the Oeste region of Portugal regularly host street markets, with excellent stands offering a wide range of food, clothing, flowers or antiques. During December, the variety usually increases with craft markets and festive activities. You can check out this link for information on 41 Christmas markets in the Centro region.
It is also common to find the most central streets of the cities to be pedestrian-only, or to have very restricted traffic, favoring a quieter walk, and concentrating in them the most popular shops of the local commerce.
In Portugal, we also often see many shopping centers, with a good combination of clothing, leisure, restaurants, and other services. In this type of setting, the client usually loses a bit of authenticity in exchange for comfort, free parking and a more comprehensive range of items offered. The two most popular in the Oeste region are the Arena Shopping of Torres Vedras and La Vie Shopping in Caldas de Rainha.
And for those who do not mind doing more kilometers or who want to spend part of a day in Lisbon doing some shopping, there are several excellent shopping centers in the capital. For its great value for money, we like the Freeport Lisboa Fashion Outlet, in Alcochete, on the south side of the Vasco de Gama bridge, which gathers the best fashion brands at very reasonable prices. Their concept is an open-air shopping center, so it is probably not the best option if the day is rainy, cold, or very windy. The alternative may be the Strada Outlet, near Odivelas, by the CRIL ring road. And other interesting options are the huge Centro Colombo, in Benfica, in front of the Estadio da Luz, the Vasco de Gama, next to the river, and the ones in the Loures area, where you have the largest Ikea in the Iberian Peninsula, a Decathlon and the Loures Shopping. The latter has the peculiarity that includes among its many services the presence of Trofa Saúde Hospital; they have probably thought that with all the great shopping on offer, clients will push themselves too far and it may be practical that assistance is close.
Probably the best advice would be to do as they say in some ads, consume but with responsibility and moderation.