1. Get enough sleep.

2. Avoid watching too much TV.

3. Avoid spending time too much on social media.

4. Know your interest and develop yourself.

5. Speak with people full of wisdom.

6. Keep updated with current events.

7. Keep a balanced diet.

8. Try to write sometimes (like poem, diary or short story)

9. Read books or magazines.

10. Enjoy life!

I once bought a book entitled "How to Improve Your Memory".  However, the book didn't help me at all.  I forgot to read it.

How to improve your memory ? 

Try to link things similar altogether and sprawl as much as you can. Explore your imagination is another good way to cultivate your memory . But I have to remind you : most people who cannot learn language well  are not caused by poor memory , instead of lack of integration into useful sentences.