I have a few friends from SOL DU and here is their advice to get a better score in the examinations. 

• It is best that you follow the exam papers of the preceding 10 years to gain better insight into the pattern followed by the examination.
• Following the same, you should reschedule your time and make a good routine. 
• It is recommended that you study two subjects per day, allowing extra time when required. 
• Most essentially, it is best that you study at least six days per week and try completing one entire subject in a week or less. 
• Brush your answer framing skills, alongside making time to solve as many test papers as you possibly can.

Hope this helps answer your question.