I'm writing this because I struggled to find information when I had to get from Shkoder to Tirana. I relied on local information which I hope would be helpful to others if it exists on the internet. This informatin is correct as of Winter 2024.
The route I took required two buses: one from Shkodër to Tirana Bus Terminal, and a local bus into the city centre. I will describe both.
You start by getting the regional bus from the centre of Shkodër to the Tirana Bus Terminal.
This bus will pick you up near a big roundabout right in the centre of the city. The stop is mapped in OSM by https://www.openstreetmap.org/node/9712247329. It is right by a large light-up sign that says "NEPTUN". There is an image below
I was told the buses run every hour, on the hour, which matched what I experienced for my specific bus but I did find a sign nearby which listed a timetable which is shown below.
The bus should have a sign in the windscreen saying Tirana or Tirane so make sure you get on the right bus. If you have large luggage you can store it under the bus for no fee (I don't think I paid extra for it at least). Go ahead and chuck your bags under and then find a seat on the bus; you buy your ticket later.
Once it's time for the bus to leave, the doors will shut and you'll be on your way, but you still might not have bought a ticket yet. The bus might pick a few more people up along the road out of Shkodër. Once I was out of the city, the guy working on the bus came around and collected the money from everyone.
The ticket was 400 LEK. This is cash only.
The bus might make a few stops on the way to pick up or drop off other people, but you should stay on until the end. My bus dropped me off on the road next to the main bus terminal in Tirana which was good since this is also where the local bus stops. The location of this stop in OSM is https://www.openstreetmap.org/node/5342454642 You should be able to grab your bags yourself. There was no bag ticket system on my bus.
You can choose to go somewhere else from here but I had to travel into the city centre so this is what I will describe.
I have no idea how often these buses run but I saw a few around. At the same bus stop linked above, you should look for a long white bus (mine had three sections to it). Unfortunately I couldn't find get a photo. There was someone working on the bus who had on a hi-vis vest and was standing outside when I arrived. He directed me onto the bus when I asked if it was going into the city centre (I'm not sure if some buses go to other destinations so be careful here).
Tickets are bought on the bus with cash. The same man in hi-vis came around once the bus was moving and sold the tickets.
The ticket was 40 LEK. This is cash only and seems to be a fixed price, regardless of destination or distance.
I got off the bus around here https://www.openstreetmap.org/node/11189542921. There were many other passengers getting off here too.
Now you are in Tirana city centre.