Urban tinies must adapt to their outside environments just as any regular human does. The biggest difference for these tinies is that they scavenge their food and belongings from the humans they live with. Most tinies have their nests in attics or hidden corners of basements, hidden in the walls and behind boxes that haven't been moved in years. Their biggest challenge, unlike their wilder brethren, is to avoid being seen by the humans.
These tinies are experts in the art of refashioning human items for their own use. They don't really need to worry about food or water since they often go on scavenging expeditions at night and can quite easily keep their storages full. Most tinies live in places where they have access to the outside as well, in case the family adopts a particularly ferocious pet such as a cat or a dog. This allows them a way to more easily escape from the pet or even if they have been seen by humans.
Tinies really like to live in office buildings or warehouses. This way, they don't have to worry as much about the threat of pets. In the case of office buildings, there are usually a few storage spaces which are largely ignored. They even live in homes designed to look like boxes of paperwork that need to be stored in perpetuity. The only risk this poses is someone searching for specific documents which might be stored in such a box. However, this rarely happens.
Warehouse tinies tend to live in places where they can make things and still avoid being noticed. These tinies make things to sell such as scissors, needles, knives, cutlery, and so on that are tiny sized. This makes life easier for any tiny fortunate enough to be able to purchase these.