I'm not going to beat about the bush, because you know what my opinion is already; the most important thing about nice streets is that they have very low motor traffic flows with access limited to those who really need it.
Earlier in the week, I found myself in Exmouth Market, Clerkenwell. There is nothing particularly flash about the street, it is just very pragmatically paved and managed. The businesses spilling onto the pedestrian space could be better managed (some of it will definitely be an issue for visually impaired people) and there is a bit too much street furniture, but the street gets on with its job without fanfare or pretension.
Doing a bit of going backwards and forwards in Google Streetview shows that the basis of a nice street has been around for a long time and that is the pedestrian zone which operates 7am to midnight, 7 days a week. There is an exception which allows loading and the street is one-way.
Its modern incarnation maintains the pedestrian zone, but a restricted parking zone has been added (operational all the time) and loading is banned between 12pm and 2.30pm, Monday to Saturday. In other words, one could drive a car along the street between midnight and 7am, but not park. One can also load all week, other than the 12pm to 2.30pm period between Monday and Saturday (there are loading laybys provided).
What this all means is that unless you need to get into the street with a motor vehicle out of hours or for loading (other than the banned hours), the street offers no advantage to rat-running. There are also camera signs showing, so I'd guess that CCTV enforcement is taking place from the cameras in the area!
The traffic management also uses a couple of other streets to form traffic cells for motor vehicle access which essentially means that access is provided (subject to the controls I mention above) and it allows a section at the south-western end of the street to be totally closed to motors. The diagram below shows the one-way loops (green) and motor-free section (red).
Cycling is partly two-way, but the signage is a little confusing and not all streets in the wider area can be used for two-way cycling. A bit of a tidy up and explicit permission using contraflow signage would be the icing on the cake. Google does shows things changing and so it could be seen as a work in progress.
The "footways" are of (concrete, I think) block paviours - I would add that the whole area is a level surface which is great for pedestrian use. I realise that level surfaces are controversial, but in a mainly pedestrian area, they are generally appropriate. Interestingly, there are bollards used to edge the carriageway which hints at out of hours loading abuse.
There are also cycle parking hoops on the footway edge and so with the bollards, it can give a bit of "semi-protected" space for those needing a more defined footway area. If you have a strong view on this, please comment. The use of a level surface is pragmatic because it allows the use of the street for a market and for tables and chairs to spill out. Had kerbs with an upstand been used, there would have been a risk of trips and falls as people picked their way through at the busiest times.
There is no specific recipe for a great street and Exmouth Market is not absolutely perfect, but there are many elements which should be replicated. People often look longingly across the North Sea at what other countries do in their commercial streets, but we have plenty of examples here which can easily be copied.