You can always carry things that you find suitable during your journey but some of these are a must that you may want to bring with you as part of your everyday survival kit.
Knives – Any kind of knives, square knives, credit card knives, tactical pens, you can use any blade to protect yourself.
Shelter – Mylar blanket is the easiest and lightest option for very small sets. As you build a bigger, more advanced bug-out bag, you can include better protection. You can also search for the ultimate survival bag online and get amazing results in no time.
Fire – Lighter – Wind is the best waterproof lighter. Depending on the size of the kit you made, you can choose the size. But at least you need to have at least one way to start a fire.
Light – There may be different light sources at different locations and in different kits. But you should always have a light source. If nothing else, the mini flashlight on your keychain is a must.
First aid kit – This can be as simple as a few bandages, some alcohol, and antibiotic swabs, or it can develop into a complete first aid kit with a defibrillator. Some first aid items you may want to consider for a small kit also include duct tape, bandages, alcohol, antibiotics, ibuprofen, or acetaminophen.
Compass – You can't rely on a compass in the GPS on your phone. In the event of an infrastructure failure, the first thing you will lose is your cellular service. You will need an old magnetic compass either built into your analog clock or yourself.
Food – You can choose canned food or at least only the ones that need hot water to eat. Having a mini bottle-type container is also good to carry water or filter it.