I haven’t roasted a whole turkey in a long time because my brother always cooks our Thanksgiving turkey, but this is a tip I do with whole chickens and you can do it with turkey.
Start by cooking the turkey with the breast side down. You can cook it that way about an hour, then turn it over for the remainder of the cooking time. Doing this is supposed to help keep the turkey moist.
I have also heard (and sometimes remember) that when you have a chicken or turkey in the refrigerator, let it rest breast side down so the juices will gather there and help keep the breast moist.
I have been experimenting with brining recently and am hoping that my brother will brine our turkey this year. But that’s a post by itself and one I hope to share with you soon after Thanksgiving. However, if you don’t already brine your turkey, you might want to look into it. There is plenty of information that can be found from a search.