How?
I keep one row of ammunition for my molten fury and phoenix blaster. Half a row of fully stacked healing potions (I acquire this many on online servers by trading)
I have another row for other weapons I often use, including dark lance, sunfury and star cannon.
On my top row thing that you can switch through when you aren't in inventory, forgot what's it called, I keep ivy whip, flamarang (always), molten fury/phoenix/starcannon, night's edge/sunfury/dark lance, flamelash/demon scythe, molten hamaxe, molten pickaxe, one stack of healing potions, orb of light and finally, magic mirror.
This leaves me 8 spots for things I pick up while adventuring.
Here's a screenshot to show you what I mean (the top row thing at least)
