A day pack is very convenient when you have some stuff to carry around.
Don't worry if you don't have one. The instruction below shows you how to make one from long pants.
You can change the length of the string in the belt loop to adjust the day pack to your size.
1. Tie each hem with a piece of string.
2. Bend the pants at the knee, thread the rest of the string to its belt loop.
When the string is tightened and closed, you can carry around stuff inside the waist. The legs will work as shoulder straps.
Quoted and translated from" 200 survival techniques in outdoor life"