You should combine all the techniques you know wisely. Prioritizing images, differentiated locations (even images could be locations) and associations (you make them connect with literal images or you noticed patterns).
There are plenty of natural triggers to make memories, if that what you meant. Some research on psychology is good (magicians like Derren Brown put it to use all the time). For instance, if you do an action when a recurring idea is being said, by doing the action later you could trigger your recall of the associated event.
My process is transforming any idea into my thoughts:
First I gather the data to memorize.
I transform the data into my own expression of them.
I use the method of loci + linking system.
For studying I have two options: I simplify or I copy. Then apply the methods.