I've tried different ways to keep items easily accessible.
I tried the Maxpedition Cocoon pouch because that's one thing it was made to do. It's a great pouch, but it didn't work on the shoulder strap for me. When mounted vertically, small things can fall out too easily (for me) when I unzipped it. I also discovered that I didn't like anything attached to the shoulder strap that way.
I also tried hanging a Cocoon (or other type pouches) on the sternum strap. It was better, but I didn't really like it.
Whether I'm carrying a "big" pack with a "real" hip belt or I'm carrying a "daypack" makes a difference. I can put pouches on the "real" hip belt without much notice, providing easy access to anything I want to put in them.
With a "daypack", I don't like anything on the waist strap (which is almost never used by me). I sometimes put a pouch on the bottom part of the shoulder strap. It rode against the back of the pack, and I could pull it up to access things. I don't do this much anymore. Most of the time with a daypack, I put a pouch on my pants belt to carry all the little things I need to access and/or carry a pouch on my chest in a manner similar to the Hill People Gear Kit Bag (I often carry a chest pouch with a "big" pack also.). These pictures are relatively old.
Belt pouch - I'm using paracord for belt loops most of the time these days.

Chest pouch - I use 1" webbing and ITW G-Hooks.

These aren't the only ways to do it, but I like them.