As you know, robberies do happen in Latin countries. The tactic to fight back is fraught, in potentially dangerous places it is better to have a small amount of money, old credit cards and a phone, which it is not so sorry to part with. It is better to hide the rest of the things away, as the robbers, as a rule, are in a hurry and do not search.
Here are some of the caches I built for myself and often used when traveling in Argentina and Chile:
1) Cuff with zipper on the leg. Proved to be the most convenient when frequent access is needed. I hid credit cards there, sometimes the SD card from the camera.
2) Armpit holster bag. Crafting requires skill. It took small plastic backpack buckles, iron carabiner hooks, a child brace fixture and two ribbons. It was better to take black ribbons, my red ribbons sometimes treacherously “shone” in the shirt collar. In such a bag, I put my passport and phone, and, accordingly, put it under my clothes. It is better to put your passport in a bag, otherwise it will get wet at a time, especially in the heat.
3) Belt with zipper. You need to find a soft one so that you can sew a compartment with a zipper to it. Someone uses a fabric sling instead of a belt, providing a buckle. We hide the bills folded along in a cache. Convenient mainly for long distance transportation.
4) Internal hanging pocket. Simple enough to manufacture. Hang it up by the loop on the trouser belt, but let it go inside the trousers. It was more convenient for me when such a cache hung in the back pocket. The passport, placed in it, may bend slightly, but not critical. Do not forget here about the moisture protection bag.