Time management is the greatest challenge for me in high school. I have to take good care of my subjects, activities, social life and rest. I was often angry with my family member just because I didn't plan my time well. For example, I might shout at them for troubling me when 1 was working. And sometimes I might say something bad to them when I missed deadlines(截止时间), even if it was actually my fault(错误) to put everything together at the last minute.
As time goes by, I realize that time management is very important in our everyday life. The best advice to deal with time management is "break it into bits". It's really important for you to learn how to break a big project into small, manageable tasks. Then you can work progressively(循序渐进地) and have a sense of achievement whenever you've done with a small part.
Another piece of advice is to plan a timetable for yourself. It doesn't have to be the one that you follow completely. It's just there to serve as a guide. You can compare your actual timetable with the planned one to see how well you actually use your time. The final suggestion is to always set deadlines for yourself.