Here is one simple tip for you --
TURN ON ONE-HANDED MODE
Not everyone will be able to reach the top of the 5.8in Galaxy S8, so you might want to turn on the very handy one-handed mode.
Go to Settings -> Advanced -> One-Handed Mode to turn it on. You can toggle it with either a diagonal swipe from the bottom corner, or by triple-tapping the home button. It'll shrink the screen and make things much easier to reach
Congrats for awesome S8