Reading text books, magazine, fictions, cartoon books, journals and etc.
Play Kara OK and sing songs,
Practise musical instruments,
make phone calls with your friends,
Do personal hygiene and cleanings and house keeping,
Assembly and compiling the phone books and your school records.
Revision of your studies.
If you are already in work, then concentrate your efforts on finding out where and how to upkeep your competitive edges, such as go to check out Continue Professional Developemnt programs offered by various institutions.