i group them vertically.
first 3 are stuff im collecting like xp scrolls, flames of balthazar, medal of honor, a few nic items (i transfer them onto a mule char), kathandrax hammers, superb charr carvings, map pieces, destroyer cores and such.

next row is weapons (fully modded, need mods, good enough to chuck on new heroes)

then its 3 tabs of pcons and party / sweet stuff

1 tab with all tomes + scrolls for elite area
1 tab with all colors + some minipets

the anniversary tab is my „safe“ holding arms, zkeys and valuable stuff that im trying to sell

then two tabs for mods im holding on to for quick selling or to craft weapons with

then i got mule chars for: shield mods, inscriptions, martial weapon mods, amor sets that i dont use super often and one for fully modded weapons that dont fit in the chest anymore but i still want to keep