Okay, Ive noticed that alot of guildies are having trouble managing their bank and bag space, I may be able to help. With this guide I have more than enough room in my bank, and dont have to worry about putting points into crafting on my toons I quest/pve/pvp with. The downside to my method, you will have a dedicated crafter/researcher so you might have to start researching from scratch.
1. Make a dedicated armor and weapon crafter. I have a crafter who has reached 50 in every crafting line. Easy way to do this is: Level toon up to VR1, get a tone of skyshards and skill points, respec all his skills (need about 115 I think), dump them all into the crafting skill lines. This guy is really important because I can load him up with refined mats, trait stones, motif stones, and tempers without having to keep them in the bank. This guy alone frees up more than 100 spaces in my bank.
2. Pick and chose. This is probably the biggest way to manage inventory spaces. If you have 300 iron bars but dont have any character of that level who would need iron bars, get rid of them. Put them on a pack mule, sell them, trade them to a guildie, etc. If you eventually need them for something, you can always pull them off a pack mule or buy them from a guild trader in Rawl'ka.
3. Keep your Raw mats in the bank. Whenever Im out questing, I get alot of these mats. Instead of putting them on my crafter, I leave them in the bank. Whenever I get on my crafter, I will refine the raw mats and they will enter my crafters inventory. So basically each time I refine, those raw mats will leave my bank and enter the stacks of mats that are already on my crafter.
4. Horses aren't just for riding. I bought all my non questing toons a white horse or a bag horse and leveled it up to 50 with nothing but oats. Since they don't do a lot of riding and mainly just need bag space, its the best option for them.
5. Bank and bag space upgrades. I maxed out all my characters bag space with upgrades. Sure its expensive, but very valuable if your a hoarder like me. Im currently on 170 bank spaces but I could get by with 150 easily as it does get expensive.
6. Bound items, costumes, trophies, fishing bait. I have a pack mule for all of these things. If you get a rare drop from a dungeon or a piece of gear from trials that you want to keep but don't necessarily have use for anytime soon, put it on an alt. Its just gonna sit in your bank collecting dust and when your ready to use it, swap it into your bank. Pack mules are probably the easiest way to free up bank space.
7. What to leave in bank. So since all of my questers will pick up raw mats, runes, alchemy plants, soul gems, potions, and more every time I play with them, I leave them in the bank. You can refine, craft glyphs and make potions with mats that are in your bank, so just leave them there.
8. Stacks and stacks. After lots of deconstruction/refining, my crafter will get near 1000 pieces of nightwood or over 100 bones. Since each item (except Ta) will make a new stack after 100, 1000 nightwood is 10 inventory spaces. Keep 200 or so and sell the rest. Im never gonna use 1000 nightwood, so I sell off 800 to keep my bag space cleaned up. Same goes for style and trait stones like diamonds and aldamine. I dont need over 50 of them, so If I get close to a stack, Ill split them up and destroy them.
9. Use the mail. You can send items to other places and let them know to return to sender. The mail (and all attachments) will sit in your mailbox until you withdraw them for easy item management. Remember tho your mailbox can get full and mail has an expiration time (30 days?)
With these tips, I am able to have 100+ bank spaces free at all times. Sometimes I will fill it up with purples and blues that need to be deconstructed, but thats easy peasy. Log onto crafter, go to each station, decon, log off. Everything from deconstruction will go directly into my crafters inventory. Since he is already holding those mats, the items will fall into those groups and not take up any more of his bag space.
4 Toons (1 of each class) that I quest, dungeon, pvp, trials, etc with. I only give them items that they will need to use so they have a pretty free inventory for loot.
1 crafter: Does all my researching, crafting, deconing, food and potion making. He holds all my hides, metals, wood, cloth, style stones and trait stones.
1 barracks toon: A packmule for items that are unique or armor sets I hold onto for future use.
1 Trophy mule: Holds trophies from quests, costumes, fishing bait, and misc items I want to keep.
1 guild donations mule: This guy only carries donated items from guildies like you. It keeps everything separated from my personal stuff, which is nice.
BANK: Raw unrefined mats, alchemy ingredients, provisioning ingredients, runes, potions, soul gems, food, pvp stuff, and weapons/armor to sell or decon.
I hope some of these tips help you guildies manage your bank and bag space. If you have any questions or additions feel free to reply here or shoot me a PM.