I know next to nothing of hiking, so I’d be interested in hearing of your trips and tips and whatever else!
My limited knowledge roughly amounts to go with someone (genuinely) experienced, have more water (and probably food) than you’ll think you need, good footwear, be wary of the mystery berry, and don’t try to pet/touch all the wildlife (no matter how cute they may seem).
Walking up a mountain to start then back down is 1/2 as hard as walking in to a valley and then climbing out even if total distance and elevation are the same. Relationships have been destroyed over such mistakes.
If you are going alone or small group. Tell people when/where you are going how long you expect to be gone what trails you expect to take and make sure you call them to report youre ok when done.