Here is one figure I used, it is a cartoon of what various RNA viruses look like in the EM, drawn to scale. (It's from Lange). The morphology is quite diverse.
Our attention is currently focused on the one in the middle of the top row. Now, there are a lot of properties that viruses have: is the genome RNA or DNA, single- or double-stranded and so on. Also shape of the capsid, lipid envelope or not.
I had a hard time remembering all this stuff (I actually could not), so I made up a picture that was successful. This is the general organization for RNA viruses.
Here is how I used it.
Then you memorize a pattern of active dots for each property that you need to know. I required them to know which viruses were enveloped, and which had segmented genomes.
There is another thing that's a bit of a detail, but some may find it useful. There is so much material in lectures, especially to medical students, that it has been described as "trying to drink from a fire hose." I am very sympathetic to them on this issue. I adopted the strategy to color-code text on slides: blue means you must know this, black means it's important and you may need to know this, and gray means it's something I want to talk about but you do not need to know this. And then another color, like salmon, for the title of a slide to tell what it's about.
Here's another summary slide showing the Arboviruses. These are "arthropod-borne" viruses (i.e. insect-borne).
This is the sum total of Coronavirus information (characteristics of the infectious process were taught later, in the context of lung infections).
Finally, here's another cartoon of DNA viruses.
I was pretty proud of myself for coming up with that aid to memory.
I have put links to the two lectures up on Dropbox. I can't guarantee they'll stay up for ever, but we'll see. Introduction to viruses Virus systematics
