When I leave the house, the core items are: Tier one (absolute essentials) : 1.1: Keys. When I leave the house, I need to get back in. (1.2: Clothing. To protect my body from the environment, maintain body temperature and prevent awkward situations, I wrap myself in fabrics) Tier two (so essential, even non EDC People carry them): 2.1: Wallet & Smartphone I set those two on the same level. I carry both on most occasions but might carry only one sometimes, depending on what I want to do. Tier three (the first one where EDC items appear): 3.1: Flashlight The flashlight is the EDC item that I use the most, so it makes top of the tier. Depending on the occasion I have at least a single AAA light on my person anywhere I go. The darker the destination, the more light I have on me. During summer I usually only have and use the AAA, during winter I carry more lumens in my pocket. The flashlight on my smartphone serves as a backup. 3.2 (work days [becomes 3.3 on non work days]): Pen During work hours I need to write down stuff quite frequently. Either some orders written on a post-it and given to someone (because they come back and ask for details they forgot every minute) or a multitude of other stuff. My workplace is strewn with pens in tactical positions. There are at least twenty lying around at all times. And every single time I need one, they all are somewhere else. Fed up with this, I started donating valuable pocket space for a pen. 3.3 (work days [becomes 3.2 on non work days]): Knife On days without work, I still carry the pen, but If I had to choose between a pen and a knife, I'd choose knife. For me a small pocket knife with a blade of max 3" and a deep carry clip does the job. I often cut cardboard boxes to size and hate to do it with a utility blade for fear of the thing snapping when I lean on it. That's about the heaviest work I can expect my knife to do. I don't have to elaborate on the other practical uses of a knife in this place of all. Tier four (stuff I carry often, but not always): 4.1: My Bag I have a sturdy and good looking messenger bag (Freitag Dragnet) made from used truck tarpaulin that has served me well in the past 15 years. It is pre-loaded to expand my EDC, bring redundancy and refuel. It carries a refill for my pen, a spare battery, a Leatherman Wave and a small flashlight in the front pocket. The rear compartment of the main pocket holds a waterproof pouch that has my 'digital' requirements covered with a pair of headphones and 1/8" to 1/4" adapter, a small USB powerbank with a short cable and micro USB to USB Type C adapter and a small USB wallwart. The main compartment is empty, except for a cloth shopping bag lying folded on the bottom. This is very good to wrap fragile things, or for shopping. 4.2: Bottle When I leave for work, I carry two stainless steel bottles in the bag, one filled with 1 liter of water and just a spritz of lemon (to make it taste like something) and a smaller one filled with coffee (or on rare occasions with tea). When I leave for anywhere else, I usually carry water, too. I forget to drink enough and my body runs fine on incredibly small amounts of liquids, so I like to bring water everywhere in my bottle to better monitor my intake.