I talk to them and throw cashews at them from my balcony. They have gotten pretty close in a matter of weeks, despite having a cat (she is scared of them tbh and I think they know). I also leave some nuts on the railing near my back door for them to grab (make sure they watch me place them) so they can get them when I go inside (my cat loves watching this and the little birds). Though sometimes they do a quick grab if there's some distance. It really is a lot of fun and to watch their behavior patterns. For example, there will often only be one or two on the ground and checking things out while more in the trees or roofs. Once they realize those two are not dying from the food you feed there's a few caws and more come down. The spotters are the ones that make the quick grabs at my railing and it took a bit for this to happen so I think they trust me some. In a different place I lived one crow came right up to me, just out of arm's reach, for sunflower seeds. They really are smart and friendly creatures. They'll even talk back a bit.