I just found video by Urban Dawg on training leash reactivity. I found it really helpful to see someone else doing this in practice, especially the bit where the dog unexpectedly has to pass another dog that is tied up. This is the kind of situation I find a real struggle with Dog2. It's great to see exactly how to deal with it.
The main thing I took from the video is about the frequency of reinforcement. I knew to give treats but I didn't know to give them so often! They have subtitles which say e.g. they gave 7 treats in 26 seconds.
I found the video really useful, so I thought I'd share :)