Just a question, have you ever thought of decorating your school bag? It can be done, but how you do it without doing it in a derogatory manner is another question to be asked.
Teenagers love the fun, while I was in secondary school it was very important having the brand name bag and decorating it. Everyone used colourful threads to decorate their bags and they did it in a particular style. Some made stars, some used the thread to create flowers, to create trees, hearts etc. The aim was to follow the trend and have the style.
You may ask yourself should you do the same?, yes you can it is not all over the world as yet. Choose colours that blend and are suitable for your bag. Keep in mind, that you should not create any styles that are negative and do not promote anything that is against the school rules. Do this style only if your school allows you to attend with school bags as such. Do what you are comfortable with, do not do it because everyone else is. Think before you act a saying that should be applied.