Meet with your teachers. Ask your teachers to show you your latest grade. Grades are calculated using points; this will tell you how many points you need to bring up each grade. Inform the teacher of your desire to raise your grade and ask about opportunities for extra credit.
Attend class. Every class builds on the class prior to it, so taking a few sick days will cause you to fall behind. If you do have to miss a day, be sure to get notes from a classmate and complete any missed assignments.
Focus your studies. While it is ideal to devote equal amounts of time to each subject, this is not always feasible during a two-week crunch time. Focus your study time on your weakest subjects. Use study methods that work with your learning style, such as flash cards, memorization techniques or working with a study partner.
Stay organized. Prioritize assignments and keep them in a neat folder. Stay on top of due dates and read all handouts or assigned reading within the two-week period.
Study for exams. If you have an exam at the end of the two weeks, begin studying right away. A little bit of study each day is more effective than an all-nighter the day before the test.
Prepare for a final project. A high score on a project can be enough to raise a letter grade. Start projects early and have fun with them. A class project is an opportunity to use your creativity without as much pressure as a timed exam.