As someone who has now owned a very reactive dog and worked with trainers, and been bit while interning at the vets, the best thing to do is actually just ignore the dog. If the dog starts leaning into you, showing loose body movements, and typically large tail wags, these are pretty good signs they might want to be pet. As you also mentioned, don’t look over them; additionally, no fast movements, and you really don’t need to offer your hand - they can smell you from where they are.