Happy new camera! I love mine.
I like to keep things simple (for my poor little brain) so I shoot in Manual with Auto ISO. The "SET" button is assigned to exposure compensation and auto focus is set to "Back Button" (AF-On button). AF is in servo mode all the time.
This is what I use for everything on both my 1DX and 7D2 as I can adjust everything I need without even opening a Menu. If I need to focus manually then I just don't press the AF-On button. If I need slow/fast shutter speeds then I just twiddle the front dial - more or less depth of field then I just twiddle the rear dial. If I wan't to over/under expose then I just press the SET button and dial in what I want with the front dial. This is very quick to do and allows 3 or 4 different exposure levels on a circling Buzzard. The whole advantage of the setup is that there is no need to take your eye away from the viewfinder, pretty much regardless of what you are shooting.
Naturally you need to keep an eye on the ISO (don't want it getting too silly!) but that is in the viewfinder - no need to loose your subject?
This works very well for me - give it a try, you might like it 


R5 , 600mm. F4 L IS II , RF 100-500, EF 100 F2.8 L IS macro, 1.4 Tc.III . 
