This isn't something to make a major trip around, but if you happen to be in the Austin area, a fair number of egrets and spoonbills seem to be roosting or gathering along Onion Creek in McKinney Falls State Park.
They roost in the tall trees along the creek, then come out and sit in the sunlight for a while before heading out for the day. I've been the last 2 Saturdays and both times they seemed to be coming of the shadows starting around 9:00 and hanging around in the open until at least 10:00. If you're lucky you might see 20-30 of them in a single tree.
If you take the Onion Creek trail starting from the visitor's center, most of them will be along the creek after the primitive campsites end and the trail pulls back from the creek a bit. You have to push your way through the underbrush if you want to get close, or you can stay back and shoot over the brush at the ones in the treetops. Great egrets seem to prefer staying high up in the cypress trees, snowy egrets stay closer to the water, and the spoonbills hide from my camera.