Teaching focus

I have a Mal mix who is very sight orientated. She is always in scan mode. I see so many videos of Mal owners who have dogs completely focused on them when out in public. I have recently started trying to train mine to be more focused on me than EVERYTHING else by giving her food any time she looks at me during our walk around the neighborhood. Even if it's just a glance or she looks at me then immediately my hand waiting for the treat. At this point I take it.

How do I advance from here? What techniques did you use to get your dogs full attention? I'm not going for full attention but rather her checking in with me is situations where she would normally over focus on what ever it is she focuses on.