(Posted with better images) I have had the overall layout of this for some time but decided to change some things since the latest patch along with going full OCD on items for the Gallery. The most recent changes are G and H as I didn't like the existing setup I had. I also added C and I as I didn't want to expand too much more North/South and had the room to go East/West.
** Between C/E/L this contains what I believe to be every obtainable item (excluding every food recipe as even my OCD isn't that high). ** I broke down each section below (I had to remove a bunch of text to allow this to post and then split it). I also include a couple map screenshots to show the overall world and base (the different coloring on the outside of the moat is that I surrounded the base with Radiation Crystals, which you can see at the South End of the Base Image.
A - Serenity Grove (Cherry Trees)
B - Beach Farm
C - Seeds/Non-Fish Food/Golden Non-Fish Food/Any Epic Food Items
D - Dirt/Stone/Mold Farm
E - Workstations/Workbenches/Anvils/Storage
Atlantean - Slime/Holiday Chests + Food/Potions
Ivy - Extra Workstations/Tombstones/Potion Materials
Golden Titan - Ancient Coins/Farming Tools/Pedestals + Paint
King Slime - Ancient Coins
Floating Titan - All non-Slime Chests/Merchant Summon Items/Core Items
Morpha - All Wood Types/All Ore Bars/Torches/Spare Parts/Glass/Fiber/Wool/Strolly Poly Plate/Radiation Crystals/Upgrade Gems/Ancient Gemstones/Mechanical Parts