If you're a regular reader of this blog, you'll know that I'm a fan of narrow streets. It's one of the reasons I have been such a supporter of laneway housing here in Toronto, and why I think they should ultimately allow for some non-residential uses .
If you have narrow streets and reasonably decent buildings that frame them, you have a base condition that has worked remarkably well since the creation of cities. Almost by default, and even if you don't have proper sidewalks, it is going to feel pedestrian-oriented.
The challenge, however, is that it's usually difficult to create these after the fact. Street networks are powerfully sticky; they generally don't change unless you have someone like Haussmann rebuilding your city. So if you have these in your city, try and take advantage of them. You're fortunate to have them.
The above two photos/measurements are from Milan. Both streets are around 20 feet wide (or 6 meters), which happens to be the required width of a standard two-way drive aisle here in Toronto. It's a good example of how differently cities can view and allocate space.
You can do a lot with 6 meters.