A language learners lexis can never be good enough, in fact, it is an element of language that never ends. We all learn new words every day, even in our native language. What happens is that it just becomes easier.
Focus on your interests: when learning new vocabulary, you should always start with what you think you are going to use most. Begin with your interests and favourite topics, and then the types of phrases that you will use every day. A great way to take this a step further is to take common words and focus on word families. For example, the verb “spend”. You need to know its form as a verb (spend/spent/spending), noun (expense, expenses), adjective (expensive) and adverb (expensively).
Take notes: to learn a new work, you need to write it down when you first see it. This way you can focus on what you need to improve. The Germans have a phrase for this “Was man schreibt, bleibt”, it means, what you write, remains. If you do not write it down, you will forget it.
Learn it as a phrase: you must avoid learning random words as you will not be able to remember many and they will be easily forgotten. The key is to put new words into a phrase and use the phrase as quickly as possible.
Mnemonics: mnemonics are strategies and processes that trigger memory and help you to remember. It is a good idea to make an acronym to remember something, such as our PASS method (Prioritize, Apply, Say, Search). The use of images and stories are also very useful to be able to retain large amounts of information.
Recall: you need to use words frequently to avoid forgetting them or being rusty. If you do not recall words often, you will have “tip of the tongue syndrome”, in which you know a word, you can understand it, but you can not say it when you need to.