A number of techniques have been designed to "improve" memory - techniques known as mnemonic strategies. Most mnemonics involve a straighforward and familiar principle - namely, that organization helps. If an organization can be found within the materials, then this will lead to good memory. Of an organization cannot be foudn, then often an external organiztion can be exposed on the material, like peg-word systems (example make a rhyme, connect things you want to remember with each sentence).  Some mnemoinc strategies rely heavily on visualization, other do not. Mnemonics work because they impose an organization on the materials to be remembered, thus establishing connections between the material and some other easily remembered structure. But let's alos note that there's a downside to using mnemonics in educational settings. In using a mnemonic, you typically focus on just one aspect of the material to be remembered. This focus guarantees that the selected link receives much attention and so is wel established in memory. But focusiing in this way also means that you won't pay much attention to other aspects of the material to be remembered. As a result, you may cut short your effort toward understanding this material, and likewise your effort toward finding multiple connections between the material and other things you know.
You would be better served by a memory strategy that lead you te seek out multiple connections between the material you're trying to learn and things you already know. It will foster  your understanding of the material to be remembered, and so will lead to btter, richer, deeper learning. The multiple links will also help you to retrieve this information later on: memory connections serve as retrieval paths; and the more paths there are, the easier it will be to find the target material latter.