If your Pockets aren`t enough
Blanket roll or horseshoe pack
If have a tarp or blanket, you could make a blanket roll to carry your gear in.
It doesn’t hold a lot of gear, only the essentials.
This method has been used by soldiers in various armies in earlier times.
Fold your tarp or blanket (or poncho as I use for illustration).
Lay your gear along the edge of the blanket and roll the blanket up.
Tie off in both ends and in the middle if needed.
Connect the two ends of the roll with a piece of string and toss it over your shoulder and you’re on your way.
Just use thicker string than I`ve done on the pics below, or you are in for an uncomfortable haul.
The blanket poncho could also be rolled length wise and tied together in the ends forming a horseshoe.
Rucksack from a bag
An old bag could also be used to make a primitive rucksack.
You need a bag (plastic, jute etc.), a little rope (about 2 metres) and three round pebbles. The first pebble is laid on the inside near the opening of the bag.
The rope is the fastened on the “inside” of the stone.
The stone stops the rope from slipping of the bag.
The two other stones are then used to secure the rope to the bottom corners of the bag. Make sure the loops are long enough to carry the bag on your back.
For a more comfortable pack one could make a frame and attach the bag to it.