I also do not have other fish in the same tank as the infants, because I don't want anyone to mistake them for a meal.
But where my largest angels reside, I have dither fish. In the video below, you'll notice even while Lindsay Buckingfish was defending his corner from Pipsqueak Littlefish, the smaller fish - primarily tetras - continued to swim as though nothing was amiss.
Dither fish are fish that are generally out in the open swimming and having a good time. Angels move more slowly and they tend to be very cautious, even shy, when they are not completely at ease with their surroundings. Dither fish are more gregarious and because they are openly swimming and having a good time, they send signals to the angelfish that all is well and they are safe. This, in turn, gets the angels out from behind plants and into the open.
In my 70 gallon tank, I have a variety of tetras. They were carefully chosen for their colors and their size - but most particularly for their peacefulness. You can not place barbs, for example, with angels because the angels' long, flowing fins get nipped and eaten by the barbs. Tetras are generally good choices, although you should stay away from the smallest tetras such as neons. If they are too small, the angels will eat them.
In my 55 gallon tank, I have a number of cories. I like these best of all because they are very gregarious, very lively, and completely unafraid of the much larger angels. They also eat any food that has fallen to the bottom and would be ignored by the angels, who prefer to eat at the surface. I also have a pleco in each tank to keep any algae down.