Now that you have practiced your points of focus: start Center, look Left, look Center, look Right, look Center, etc. (always coming back to center between Left & Right), you want to make sure that you “maintain an even plane.”
In other words, don’t let your eyes go over the audience’s head and don’t let your eyes look down at their shoes, either.   In an audition, you might have three people sitting at a table.  Not a problem.  When you perform, don’t look your auditioners right in the eyes, that can be fairly uncomfortable for everybody.  Better yet, create/imagine a friendly face right next to the face of the person in the middle.  Imagine your new friend sitting at that table.  Look them in the eyes.  This will be your center focus.
Now imagine a friendly face just next to the face of the person on the left at the table.  Left Focus.
Now imagine a friendly face just next to the face of the person on the right at the table.  Right Focus.
There you have it.  Three simple points of focus that don’t invade the casting people’s space, but that share the same eye plane for all to see and feel your vocal performance.
This works for all singers from the stage whether it be Pop, Rock, Cabaret or Broadway.
Another issue for those of us watching you; if you close your eyes to show us how moved you are by your own performance, you’ve lost us.
Next: WHEN to change your point of focus.