A picture paints a thousand words!
In the left external pocket I carry a small FAK
In the right external pocket I carry either a large lock knife or a Gerber multi tool.
Top right external pocket is big enough for a mobile phone or a small GPS.
The buckle down strap will tighten the whole bag down is carrying smaller loads.
On the front flap - small zip up pocket - spare AA batteries
Behind main pouch - large zip up pocket - Not quite big enough for an OS map
Under the main lid is a snow lock - which to be honest I don't use, but it might come in handy if carrying lots of small items?!
In the small front pocket I have 2 or 3 Greenheat sachets and a 35mm film cannister with some hexy in it.
In the main compartment I have my Crusader mug / cooker / 58 patt water bottle.
In the zip up area in front I have a mini maglite / foil blanket / lighter / home made lid for Crusader mug /
The only mod I made was to cut off all the rattley zipper tags and replace them with para cord.
Hope that helps!
Simon