When we experience something (sign, sound, taste, touch, smell) and encode that experience into our long-term memory, we also encode information about our internal and external environment with the memory.
This is why a smell of cigars can immediately trigger memories of my father, who smoked cigars.
This works well for us, because it helps us understand what is going on around us now by connecting it to our long-term memories.
When we have a sensory trigger to help us remember something, that works to help us recall.
That is why studying in the same environment as tests will be given is great.
What happens if we just can't do that?
What happens if we need to remember something that does not provide a trigger for us, like when taking a essay exam?
ANSWER
Create environmental triggers for yourself when you study,
and use them when you take your tests.
Think of the 5 senses and think of how you can use them.
Maybe wear a certain sweater vest or shirt only when you study and wear it when you take your test (sight and touch).
Add other triggers to that like cologne (smell).
Choose a cologne that you like and wear it only when you study and take a test.
If you choose to use music (sound) as a memory aid, listen to that music repeatedly to encode it, and quietly sing it to yourself when you need to recall information when taking a test.
Think of the room you will be taking your test in (sight). Visualize that or even recreate a part of it, maybe have a picture of the room, and look at that frequently when studying.
Use your imagination!