just passing along a tip I learned (through lots of trial and error!)….
training the dog to pay attention to you when you walk - I found this easier to do OFF leash. as silly as this sounds, it worked GREAT. my trainer suggested this after he & I were at our wits end w/ my B, and his issues when walking (not paying attention to me, could care less, going this way and that way, etc..)
in a fenced area, I let him off leash. and just walked a set path. casually walked. whenever my dog caught up to me, by my side, he got rewarded w/ a high value treat.
my trainer explained like this: you're a passenger in the car w/ a friend, going some place new. You don't pay close attention to the road since you are NOT driving. you're fiddling w/ radio, sipping a coffee, reading a map, looking at the people in the car next to you, etc... same for the dog. he KNOWS you're "driving". he KNOWS you're at the end of the leash, and thus chooses to let you drive while he explores. take off the leash, and the dog MUST watch you, pay attention to the driver, to get the reward.
my set path included ALOT of turns, go straight, right, left, backwards, etc... always changing it so my dog didn't become accustomed to one path.
once we mastered this skill, I re-introduced the leash, and had much better success. of course, this skill needs to be practiced ALOT.