15-30L pack (Like Osprey Escapist 18)
Buff / bandana dorag
Sun glasses
Hat
phone
Map
snacks/bars/calories for the day

ditty bag - TP, toothbrush/paste, sunscreen, first aid kit, knife, lighter, flashlight/headlamp

1-2+ Liter of water depending on weather
water filter and extra container (bladder for water collection)

wind or rain jacket
thermal jacket (fleece?)

trekking poles

camera/phone

Others Added
Compass!!
Physical map (backup on phone)

Mace or other protection (knife?)

Space blanket

I always include "The Ten Essentials" in all of my packs, without fail. This includes packs I carry when I cross country and backcountry ski.

1. Navigation. Topographic map and assorted maps in waterproof container plus a magnetic compass, optional altimeter or GPS receiver.
2. Sun protection. Sunglasses, sunscreen for lips and skin, hat, clothing for sun protection.
   3, Insulation. Hat, gloves, jacket, extra clothing for coldest possible weather during current season.
3. Illumination. Headlamp, flashlight, batteries. LED bulb is preferred to extend battery life.
4. First-aid supplies, plus insect repellent.
5. Fire. Butane lighter, matches in waterproof container.
6. Repair kit and tools. Knives, multi-tool, scissors, pliers, screwdriver, trowel/shovel, duct tape, cable ties.
7. Nutrition. Add extra food for one additional day (for emergency). Dry food is preferred to save weight and usually needs water.
8. Hydration. Add extra 2 liters of water for one additional day (for emergency).
   10. Emergency shelter. Tarp, bivouac sack, space blanket, plastic tube tent, jumbo trash bags, insulated sleeping pad.

https://en.wikipedia.org/wiki/Ten_Essentials

I do not rely on any electronic device for navigation. I always have a topo map and a quality compass (with sighting mirror, that doubles as a signal device). I always have the darkest prescription sunglasses I can get. Cataract protection and delay are important. I always carry a wool rag sweater and Gore Tex parka. I carry a space blanket. I also carry rope, 6mm - 100 feet. I've used it to cross flash flooded streams during extreme thunderstorms. In the winter for cross country skiing I carry a butane stove for warming liquids when I find hypothermic people. I've lit some fires in very challenging storm conditions to heat people up. I always carry 2 quarts of water.

I'm retired from the U.S. Forest Service, which included some time as a wilderness ranger. I was an EMT on a fire department ambulance. I've had my share and then some of emergencies and public assists in the backcountry both on and off the job. I've treated critical hypothermia, high altitude pulmonary edema, broken ankles, torn ACL's, anaphylactic shock due to a bee sting and some heat exhaustion cases while in the wilderness. I've assisted 2 helicopter evacuations off the job. I've also been involved in several search and rescues. I've seen the importance of each of the 10 essentials in assisting others and for myself in some unplanned circumstances.

On many of my hikes it would seem that there was no reason to carry many of these items, but I ended up using them. You just never know what you are going to encounter.