Packing is something that you should be able to do on autopilot. An easy way to know that you have everything you need when you’re traveling is to keep things in the same place every time you pack. This limits the need to make a mental inventory every time you pack, which takes unnecessary mental energy. By forming strong habits, you prevent yourself from making mistakes when you’re under the stress of being in unfamiliar environments. Using this approach you can pack quicker because you already know what you need.
Try limiting the number of items on your checklist by bundling items. For example, I keep all of my electronics adaptors in a pouch that I put in my backpack. That way, if I see it, I know that I have everything I need without going through each item individually.