I've added a slightly more in-depth description of my numbers system to the FAQ:
Since mid-2014, I have used a 3-digit system (one unique image for each 3-digit combo from 000-999) based on the [Major System phonetic code][9], shown below. My system is approximately ⅓ people and ⅔ objects. I place two of these 3-digit images per locus.
Each digit is assigned a corresponding phonetic sound:
0 s, z
1 t, d
2 n
3 m
4 r
5 l
6 j, ch, sh, soft g
7 k, hard g
8 f, v
9 p, b
For a given 3-digit combo, I squeeze the three sounds together to form an image. For example, 375 might correspond to MKL, so I chose “Michael Jordan” as my image for 375. 357 became “milk.” 604 became “chess rook.” 970 became “Biggie Smalls.”
Here are a few links I used to brainstorm Major system images (if you're stuck on a number, try plugging it into these for some ideas):
http://major-system.info/en/?n=279
http://www.phoneticmnemonic.com/lookup.php?num=279&submit=Lookup
http://www.rememberg.com/