This is where my using hexadecimal has come in so handy. I have a 3-digit hexadecimal number for the EO and a 4-digit hexadecimal number for the CO. I put each one in a separate location in my room. For each one, I try to make up an image to go with the number. It's easiest when there are letters from the hexadecimal in the number - that usually makes for easy memorizations. For example, recently I had 1AD for EO; I remembered that as the year 1 AD - very easy.
I'll give a couple more examples with just random scrambles I'll generate now (scrambled with the cube the way you're going to solve, but I won't bother explaining my hexadecimal packing method, since it's the memorization I'm trying to show, not the packing method). I'm just going to put down the first thing I thought of - it's similar to what I'd come up with doing a multiBLD for real.
L' F' R U D' L F L' U D2 L2 B R2 F U2 B L F' B' D' F' R L' F B'
EO: 797 - I graduated high school in 1979, so I'd remember a group of seven people from my class graduating (probably throwing hats in the air)
CO: 015C - I'd think of 15 cassettes stacked in piles, perhaps 3 stacks of 5.
B2 F' L R F2 B' U2 L' R2 U2 L' U B F L' B D' F2 R' D' B2 L B' U2 R
EO: FAF - I use "Fat Albert" as my image for the letter pair FA, so the first thing I thought of was "Fat Albert flying".
CO: 02D4 - First thing I thought of was 2 packs of D batteries, with 4 in each pack.
I have recently switched to M2, so I don't need EO anymore for 3x3x3 multiBLD. However, I still do EO this way for 5x5x5 BLD (I haven't switched for 5x5x5 central edges yet).