Teach what you have learnt to others visually and vocally
Create mind maps
Study in a group
Take a short break after 45 - 50 mins of studying
Watch documentaries
Use google codes to filter the search results
Annotations:
"quotation marks" - contains all the subject you want to search
-dashes - exclude
~tilde - with synonyms
| vertical bar - more or equal to your search results. eg. Taiwan| tourist attraction| food
.. two periods - range of time eg. biology 2016..2018