When you approach any learning endeavour, focus on learning for tomorrow. When we focus on learning for tomorrow, it changes our priorities from short-term gain, to long-term learning.

When it comes to learning vocabulary, for example, this means that you learn words for the long term, so that you won't have to learn them again.

When I studied for the JLPT a few years ago, I focused on long-term retention of words and grammar points because I didn't want to have to relearn anything. I wanted to learn it once and learn it right. This means I focused effort on putting things into my long-term memory, and to do that, I had an app named 'anki', the Japanese term for memorisation.

Focus on learning for tomorrow, and you will improve.