Begin with creating the right ambiance. Ideally, you want a work-space that allows you to concentrate. Whether a study desk, an office cubicle, a cafe booth or a park bench, you need to merely diminish distractions and zoom in on the task at hand. Equip yourself with paper and pen, or if you prefer clicking, type away.
Depending on the volume of information, the time you have, and your personality, there are several methods to employ. What always helps is breaking information into smaller, more concise chunks. This allows you to identify any possible associations or common themes in the content. However vague, it will help to make headings under which you can classify material, akin to having separate drawers for socks and boxers.
For the more visual of us, image association is the ideal strategy. You can picture certain images together, or as a related cluster, as cues within a category. If that technique is inapplicable to your material, simply recalling the number of bullets or points within a certain heading will help. Akin to thought bubbles, this process remains consistently high yield also in the process of brainstorming.
Acronyms are perhaps the most favored technique of all. These use combinations of letters, with each serving as a cue. For instance, ABC refers to Airway-Breathing-Circulation, this one being the mantra for all physicians working in the ER, as their list to run through for each presenting patient. And this list actually goes all the way to Z.
You can experiment with the arrangement of alphabets, and if you invent a sentence with the first letter, you have yourself an acrostic. For instance, "Please Excuse My Dear Aunt Sally" is the acrostic for the sequence in solving math equations--Parentheses-Exponents-Multiplication-Division-Addition-Subtraction.
Once you start exploring possibilities, you may find yourself able to come up with rhymes. Challenge your memory at every chance you get. Your grocery list, the things to go during the week or day, the guests to call to your next party--utilize various approaches till you narrow down to the one you feel most comfortable with.