The Ten Essentials are not exhaustive. They were formulated by experts in wilderness travel. But they may not be all the essentials you should carry in your pack.
You need to consider what is essential for you. The primary example of this is the medicines you may need, those that work for you or are substitutes for other more common remedies. If you take a certain medicine on a regular basis, can you do without it over night? If not, it needs to be in your pack. Do you react adversely to certain common pain medicines, are there alternatives that you can take? They should be in your pack.
On a less critical note, do you commonly use hiking poles? If not, you should. These are not just to look cool but are multipurpose backcountry tools. On the personal side, they help use upper body muscles to go up the mountain and reduce the impact on your knees coming down. They are good balance tools for when nature throws you a curve in the form of a root or a patch of ice. In an unplanned overnight, they can become tent poles for a tarp. In the event of an accident they can become a crutch to help a sprained ankle or a splint to protect a broken appendage. Hiking poles should be included on every adventure.
Another item that should be considered essential is a bandana. This item is easy to overlook but serves multiple uses during a backcountry adventure. It is more than just a place to wipe your nose. It can be used as a medical tool to stop excessive bleeding, provide a bandage or sling and in severe injuries it can be used as a part of a tourniquet. It can be used as sun protection for the head of someone who forgot a hat or needs to protect the back of their neck. It can be a sweat band in hot temperatures, a dust mask in a sandstorm or a dish, wash cloth or pot holder in camp. Keep a bandana at the top of your pack.
In an era of increasing communication coverage, it is a good idea to include some way to access this coverage. A mobile phone can be carried for emergencies but may not be able to connect. You might have to walk around a blocking mountain or climb to the top to get coverage. Signal mirrors, loud whistles, two-way radios and other electronic devices like a “Spot” are increasingly used in the back country. They do not substitute for leaving an itinerary and estimated time of return with someone at home. Along with the itinerary, include the county you are visiting and the telephone number of the sheriff who controls and coordinates the Search and Rescue efforts.
All this may seem to be a daunting task. Start by acquiring your desired elements, bring them together, organize and pack it in quickly recognized packages and stow them in your pack. That way, you should have what is necessary to have a successful, safe adventure in our beautiful mountains.
If we have not mentioned something you consider essential, bring it on. The Ten Essentials are not limiting but only strong suggestions of where to start.