[This page is a complement to the How to memorize numbers and cards page]
Optional: Most people skip that step, but once you’ve chosen all your images, it might be a good idea to build some memory palace where you use them all in order, with 5 or 10 images or 5 PAO per zone. I would quickly review that palace once a while, especially at the beginning. Having that journey well memorized will help if one day you forget what 67 stands for.
Highly recommended: One exercise I highly recommend both for learning your system and for becoming faster at using it would be to gather 100 playing cards and write 00 to 99 on each one. If like I suggested you decided to use 52 of your images for both cards and numbers, you could just use a regular deck of cards and add 48 cards with writing for those 48 numbers that don’t represent any playing card. You could also buy a blank deck of playing cards on Amazon. So carry that deck around and go through it while “seeing” the associated images as quickly as possible, without any memory palace and without memorizing anything. If you’re using something like the Major system, you could just see one image at a time or practice linking 2 or 3 or 4 images at a time. If you’re using PAO, look at 3 cards at a time and practice seeing it as a single image. That exercise takes much less time and effort than a memorization session and it’s very useful to become faster. If you can convert digits and cards into images in an instant, it’s a huge time and energy saver in the long run. If becoming fast is important for you, it’s never a waste of time to go through that exercise as often as possible.