Interesting. I've not needed these aids before because I write CSS every single day, thus repetition is what makes memorize these things.
I wouldn't know that other people's aids would help you, though? When it comes to memorizing stuff, most of us have our very own way of doing it. I, for example, best memorize stuff by assigning something an object and building a story out of those objects.
When I train my memory, I do it with a set of 52 cards and try to memorize these as fast as possible. I do that by telling a story, so each card is part of a story. Or, if I have to quickly memorize a phone number, then I divide the sequence of numbers into pairs and assign each pair an object (e.g. 25 is an orange). I do it this way because I'm mainly a visual person. You could do something like that with CSS (or anything else) as well.