This backpack can be used in an emergency situation when you might have to leave your car to go for help or can be a spur of the moment decision to go for a hike at that beautiful overlook you hadn't expected. There are only 2 items required to make a useful and quick backpack to carry your water bottle, lunch, jacket and whatever you might want to take alone.
1. Extra pants
2. Parachute cord or string.
Cut the cord into three pieces. Two about 12 inches and one about 3 feet. Tie each pant leg at the bottom about three inches from the hem. Tie them pretty tight.
Pull the two legs up and tie to the belt loop on either side of the zipper. Be sure to tie them tightly.
Run the longer cord through the belt loops and use as a drawstring to close the top of your back pack. Fill with softer things on the side against your body and any other things towards the front or back of the pants. The pockets can hold your water bottle, gloves, cell phone, etc. The more pockets the pants have the better. Slip on your new daypack and off you go.
This is a good way to take along an extra change of clothes because you can put a shirt inside and change out the pants if something happens to the ones you are wearing. Have fun.