Gears are your friend.
Flat highway driving use "D" with the "OD".
Lots of hills, then "D" or "3" - without the "OD".
Going up hills that causes a lot of automatic downshifting?
Downshift manually to "3" or even "2 " on very steep hills
if you need to do so.
Follow what your drive train is asking for.
Going down hills?
Use "D" or "3" without "OD".
Using the brakes a lot going down hill?
Down shift to "2".
DO NOT RIDE THE BREAKS.
Use the breaks as need to control the vehicle.
Pull off and allow the breaks to cool if needed.
Keep your speed controlled where YOU feel comfortable
even if BELOW the speed limit. Remember you also have a
higher center of gravity that a small carm so watch the
curves and your speed.
Rain, snow or wet?
Slow down and all that apply above.
This is what I have found that works over the years.