To keep busy on a long plane flight, first thing one should opt to do is to make friends with a nearby or neighbouring passenger. This way, both will be able to chat and gossip and thus will not be bored. If that person is a shy passenger, he/she should obviously take a magazine or a book to read throughout the ride. If that is not preferred, one may try to improve his/her social skills and surely get the other to talk.
If that person has a hobby, he/she may practise it during the flight. Sleeping is always a backup option but the problem is, how long a person can sleep? There is limit for that after which, we get bored of sleeping. Another thing that can be done to enhance ones plane experience is by listening to music. Some flights also provide their own entertainment features like movies on the plane etc. So if one is on such a plane, he/she is lucky!
A good thing to do for the ones who dislike reading and talking to strangers is to keep 10-20 sheets of paper(they may be any-plain or used) in your backpack and make origami models out of them. If one doesn't know how, just fold the paper and something will surely come out!!
People also buy joke-books and comic books which entertain people of all age at all times.
Out of many things that can be done on planes, one is to visit the toilets. Don't visit the toilet before the flight and then pass your time (even 5 minutes mater!!) by sitting on the seat!
Many people also try to have fun by solving mathematics or science questions while on-board. So one may take a book that has many questions and start to solve them on the plane.
Children would love to play games on the plane. For them, a laptop or portable video games would suffice. Girls may take their barbie dolls and play with them.
One can also improve their handwriting while on the plane.Take a pen/pencil and a few sheets of paper and start writing "abcdefghijklmnopqrstuvwxyz" without spaces, or form meaningless words and write them. One may also consider to write some quotes of his/her own on the paper.
Another thing for the inventive ones is to draw their own 'mind-made' inventions on sheets of paper. Poem-writing is always an option for all.
Some people are not comfortable with any of the aforementioned tricks. They may either refrain from stepping onto the plane or find something else to do.
Thanks to those who read......
And, a very happy and busy long flight to those who want it!!