Hi Andrew,
Your idea would make the memorization challenging, I think. There is too much similarities between each images. Basically, there would be food and amount of them. You will have to memorize many details to make sure you do not confuse things (for multi and big cube, that would simply became a nightmare). For the single-image-per-sticker method, my advice is to take 24 images VERY different from each others. With very distinct images, you only need to remember vaguely one image to recall it, as even if you only remember a tiny part of it, you still cannot get confuse. Also, by wisely chosing the images, you can get some freedom. As an example, if one image is "food", then you can simply pick the one that fit best the situation. Others could be "fire", "Mode of transport", "superhero". These are very flexible. One image I like is Santa Claus, because it is vivid and bright (and distinctive). For best result, do massive use of you imagination to chunk things.
Good luck
Micael