Thank you everyone! My best advice is teaching the watch/look command. I did this to start with when she was younger and it has come in handy in so many situations, aggressive dogs having a stare down, rabbits running across the trail in front of us, at agility trials at the start line, or when she gets to crazy to correctly get her entrance into the weaves. I can just say Bella "Look" and she will make eye contact with me. When I started training for Rally, I had her heel and then asked Look, then clicked and treated every time she did. It didn't take her long before she was holding the gaze for longer and longer before I clicked and treated and this worked into her holding the gaze when I started to look forward. We practiced this, first in the house, then in lots of busy places, at the park with other dogs, bike riders, people walking by, at pet stores etc, and I was so pleased that at the trial she kept her focus.
To train this command, I had her sitting in front of me, and I showed her that I had a treat between my thumb and pointer finger. I think placed these 2 fingers and the treat on the tip of my nose or between my eyes, which of course she followed the treat and stared at that location, click and treat. After doing this for a while, I stopped using the treat in my hands and just pointed to my eyes/nose and when I got the eye contact, I'd click and treat. I gradually phased out the finger point (although she still sometimes needs the reminder). I eventually worked her from different angles and positions (standing or down). Like I said, I can't believe how many situations this has come in handy!