The EnderBags mod adds a large storage bag you carry with you that can hold 104 stacks of items. This can vastly maximize the amount of items you can take with you at any given time and all you need to do is right-click the bag in your hand to bring up the new inventory.
So essentially you can fill your standard inventory with these bags and have more storage on yourself than you could imagine.
And you can even color coordinate your bags by placing them in a crafting grid with a dye of your choice. This means you can keep like items in certain colored bags making organization a snap!
And with the amount of space you’ll save by stacking so many items in one bag, you might as well condense your chest storage as well. This means that if you have a bag that’s filled completely you’ll have 6656 items stored in one slot. Then say you fill a large chest with completely filled bags you’ll have stored 359424 items! The amount of space you’ll save by doing this over multiple large chests is astronomical.