If you plan on hiking solo, first use well-travelled and maintained trails, such as those in state or national parks, etc. You'll find an occasional fellow hiker or ranger/naturalist along the trail.
Plan ahead, use a good trail map and don't forget that you'll need time to return once you reach your destination.
Allow for that return trip; not to get caught in the dark.
Take a hiking pole or two, adequate food/water, first aid items, waterproof matches, and some stuff you might need if caught in adverse weather or even stuck overnite. (I never had to stay overnite on a day hike).
Be aware of possible t-storms forecasted and don't get caught in or NEAR one.
If you're in bear country take pepper spray and know how to use it.
Don't forget the camera and binoculars!
Now relax, take it at your pace, breath in the peace and out with the stress!