Everybody has a different way of doing things that works for them.
I always always always water in my newly planted semps.
If they are not transplants from somewhere else in my yard, but are new from the nursery, mail order, or trades then I keep them potted and in the bright shade of my back porch where they won't get direct sun for several weeks.
If they are transplants from else where in my yard so they are acclimated and have a good root system, then they get planted and watered in like any other plant.
This works well for me so far.