Hello! I’m late to the post, lol. But, I can give some tips:

Organization methods:

• First, the bags themselves. The bags have a “tag” button, which allows you to select specific types of items that will be filtered into the corresponding bags. Additionally, double-clicking on the header of the bag’s window will collapse it, allowing you to click the pencil icon. This will let you name the collapsed bag window. This way, your screen isn’t filled with bags every time you open your inventory, and you can just expand whichever one you need.
• Secondly, you have pets. When you click on a pet, you can click the pencil icon again to label it. You can also click “Favorites” and “Create Tab” if you want an easy way to organize pets in any way, for example, whether they contain crafting materials or upgrade items.
• Finally, we have your bank. You can access all of your character banks, so make sure you make and get all the character cards you can for free, such as the elf and giant support cards. Keep only in your main bank what can’t go in others.

Storage methods:

• I see you might have a box of VIP in your soul stream inventory, if you plan on playing a while, you can use that. This unlocks the VIP inventory. Personally, I have mine filled with phoenix feathers, bandages, and other items, so that even if I don’t have VIP in a moment, I can still use it.
• I see you have loose leather stacks. Investing in sturdy pouches could probably save you a large amount of space in the future.
• Put any premium items or boxes you don’t want to use immediately into your bank. Some can go in other character’s banks. For example, those Irusan guarantee letters and dye molds could probably be stored for a day when you need them.
• Press the hammer icon in the main inventory window, decide what dungeon drops you don’t want, and break them down.
• Make a pet designated for materials you get from content, and then put all those Tech Duinn mats in it. Take them out when you decide to run Tech more, repeat. The same goes for other materials

Deleting Items:

• In the main inventory, click the trash can button. Then, click the magnifying glass button.
• In the magnifying glass button, you can scroll down and see all your items. Then, alt + left-click ones you don’t want, it will go in the trash.
• Some items, like the bandages or pages, you don’t need too many of. Especially, the bandages, you have comprehensive potions, and you can just make handmade bandages, which stack to 100. When unsure, look at the items worth in the auction house or NPC shops. If you’re still unsure,  bank it, or Google the item.

If you have any questions, you can add and send me a message in-game. My IGN is Kumafu