I don’t have a bike, but recently got a Trikke that I hope will eventually be useful for transportation. Now I have to have a small backpack for my wallet and such when I’m riding (awkward to have a bag or sling pack and ride at the same time). I recently bought a small bag (wallet, phone, and card case), which I try to remember to switch from one bag to another, but sometimes forget to transfer. It’s helping me at least have the basics with me. Oddly, I ever end up on patrol without the stuff I need for the snakes! It’s the stuff for my own needs that always ends up left behind. I think I just have a limited capacity for what I can remember to grab, so I manage to grab what’s vital for the work but not the incidental stuff that I MIGHT need or that makes things more convenient.