Here is a quick instructable to help you design and create your very own bag full of handy pockets! I hope you will use this as a guideline to adapt and make a creative bag.
Estimated time: 2-4hrs. depending on your sewing skills
Old worn-out cargo pants
Belt (to be the bag strap)
Scissors (heavy duty fabric scissors recommended)
Chalk (optional, used to measuring and marking the fabric)
I used almost all of the material from the pants including belt loops, pockets, and what I could salvage from the pant legs. So be careful when you are cutting and make sure you don't ruin something you might need later.
Step 1: First step: cut up the pants
I cut the pants into three sections:
1] The top section of the pants will provide the belt loops and back pockets.
2] The middle section started right below the inseam and nicely isolates the cargo pockets and some extra material for building the body of the bag.
3] The bottom of the legs will provide nice lengths of flat material.
I cut the pant leg segments up the middle of the leg to flatten out the material and make it usable.