Speaking exam - How to score a 4/5

Four tasks:
Task one your choice of topic and questions, prepared beforehand. Task two, a picture based discussion. Task three, a role-play. Task four, a question-based conversation. Sample link here.

Grammar

• Three tenses - past, present, future
• opinion with extension
• range of vocabulary, including some adverbs. 

Communication

• Not too much hesitation, reasonably confident and if possible, spontaneous (you don't sound like you are answering a pre-memorised sentence).
• answers are consistently good.
• Your answers need to be relevant to the topic, the title and each question.

Accuracy

• fairly good accent or pronunciation, everything is understood.
• grammar needs to be reasonable correct. (verb endings, etc)

With task one, remember that it is a PERFORMANCE. It doesn't matter if the set of questions you prepared was great, it only matters what you PERFORM in the exam. 

Chunk it up and practice as if you were preparing for a theater play. Not reading, not writing, but SPEAKING IT.