Storing all your items in Minecraft (and then finding them again) can be a challenge. The chests that you learn to build early out of wooden planks are useful, but there are ways to upgrade them and also alternatives that might be worth considering!
Iron Chests
The Iron Chests mod, for instance, allows you to upgrade chests to different tiers that can drastically increase their capacity while keeping them small single block entities (instead of morphing into two block sized chests like vanilla Minecraft does).
Actually Additions
The Actually Additions mod allows you to build storage crates, which are large wooden inventories that only take up 1 block of space and that function just like chests... except you can put way more much stuff into them! Definitely a nice early game storage upgrade!
Thermal Expansion
The Thermal Expansion mod adds the Cache, which can store an enormous amount of a single type of item... very useful for things that would normally take up multiple chest slots. It also adds the Strongbox, which protects your items from explosions and can be locked so other players can't access them.
Storage Drawers
The Storage Drawers mod adds a variety of drawers that can hold a specific item each and visually display what item they hold. There are also compacting drawers that allow you to put in or pull out varying 'sizes' of that object (Iron, for example, can come as blocks, ingots, and nuggets). They also have a powerful 'Drawers Controller' which treats all connected drawers within a certain block radius as a single inventory, which means you can deposit items into the controller and it will put them into the appropriate drawer within its network (if one exists).
Refined Storage & Applied Energistics 2
The Refined Storage and Applied Energistics 2 mods provide similar advanced storage solutions in that they allow you to 'digitize' your items and store them in a massive (and expandable) item database, which enables you to interact with all of your items in a single screen, putting in and pulling out and automating anything and everything across your entire collection of items. The search options provide make locating your items easy and intuitive. Both storage solutions take a significant investment of time and resources to set up. The major difference between them? Refined Storage is more simple to use while Applied Energistics is more complex (for those that want even more technical and nitty gritty options and functionality.)
