How to organize your vocabulary

These are just some ideas:

1. Keeping a notebook to write down new words you come across is a good idea. However, you should revise  the words you've written down every now and them to make learning effective.
2. Classify the vocabulary into groups according to type of word, meaning, level of difficulty, etc.
   
3. Diagrams can also be a useful tool if visually organising words is helpful for you:
   
4. Writing down expressions, not just words, as you encounter them, will help you associate them in the future. Some words tend to collocate and appear in association with others:
• to and fro
• see you later
• do one's homework
• to make a noise
• to be in the red
• and so on