You'll soon need lights or reflectors to keep yourself safe at night as the evening are getting longer and darker. Adding some reflective tape to your backpack or clothing is not that hard. And it will help drivers pick you out from the urban visual chaos and spot you earlier. This would be a great idea for cyclists, hikers, or commuters alike.
Firstly, you will need a good quality backpack and reflective tape which you can buy easily in reflective material or reflective vest factory. And also you will need to buy a glue gun in the nearby shop. Secondly, empty your backpack and keep it clean. Thirdly, Measure the size of your backpack and cut the correspondent reflective tape. Then you can paste the reflective tape on your backpack with the hot glue and let it dry in room temperature. Be creative and make the patterns as you want. Don't forget to add some reflective tape on the front and seams to enable 360 degrees visibility. Then a awesome reflective backpack is done. You can start using it. The drivers can see you more than 200 meters away to prevent traffic accidents and improve your safety significantly.
You can also try to iron the reflective heat transfer film to the backpack for a better performance.