This is what I wear under my ghillie suit.
In the pouches I got a couple spair mags, usually 4, but can go as much as 8 depending on wich rifle I use. I also have loose ammo, food, drink, map and compas. Calculator, small binocular, range cards (prototypes for airsoft... see my sniper clinics)
I also have a secondary with 3 mags on my molle under arms panels.
This kit is light and very low profile. I keep the top of my ghillie open for aeration and accessing my gear under.