As I mentioned, there is many places to start, however we started in Theth, so will detail how to get there.
It is straightforward if you are coming from Tirana in Albania to get a local bus to Shkodër. They run every hour and only cost a few Euros. There is no need to book, all you need to do is turn up to the South and North Albania Bus Terminal (Bus Station) and tell them that you are wanting to go to Shkodër. There are plenty of bus drivers to help and all the busses will have their destination on the front.
Getting from Shkodër to Theth was a little more complicated but there are still many shuttle busses that run back and forth each day. We just asked out hostel when we booked and they sorted out some tickets for us and showed us where to meet the shuttle bus in the morning. These busses will drop you in the centre of Theth where you can either walk to your homestay or begin the hike to Valbone if it is still morning.