As a warlock in the wonderful World of Warcraft you learn to do a few things very well. You learn to deal with the fact that in WotLK you couldn't pvp if your life depended on it, you learn that being nerfed isn't the end of the world and thanks to soul shards you learn the most important thing of all: Inventory Management
I read a blogpost by Larisa (over at pink pigtail inn) detailing her woes with inventory management and decided it would be interesting to see if we can make inventory management a little easier for those who are continually fighting the bag space monster.
Let me start by saying: Bigger bags won't solve your issue. If you have a full bank now, you will most certainly have a full bank even if you stuff it full of 22 slot bags. Why? Because you're a disorganized packrat, that's why!
That's not to say it's bad being a packrat... I myself am a horrible packrat with a bad knack for collecting darkmoon cards, old world materials and even a fair set of white items. I swear that stuff will come in handy one day... yes it will... *nods forcefully*
The trick is to come up with a system that works for you, that takes away your need to analyze the situation and to keep you from thinking: 'what in the blazes am I going to do with this item?'
And for that you will need: Alts
If you don't have any alts consider rolling up a few death knights. Being as they start at level 55 they make both excellent bankers as well as profession slaves (something to power level professions on).
Of course any type of alt will do but if you're not into alts DK's only need to be levelled out of the starting zone and will make great choices.
Next it's time to run all your alts to the nearest bank and buy up all your bank slots and fill them with netherweave bags which go at a mere 8g a pop. If you can afford bigger bags then more power to you but realistically 16 slot bags should be ample space to store all your crud in. If you can't afford the bank slots yet just buy them as you go along.
If you have significant packrat ambitions then you might want to consider starting a guild on one of your alts and buying some bank tabs. Note that this method is expensive but may be a good long term solution to your storage problems.
So now that you have your alts, and they are all slotted up it's time to do the simple trick of assignment. Here's an example:
My paladin (incidentally my blacksmith) is responsible for all my ores/bars
My Druid (my alchemist) is responsible for all my Herbs/potions
My hunter (the leatherworker) is responsible for all my leathers/hides
My priest (friend of jewelcrafting) is responsible for all gems
The trick is to pick a responsible alt for each of the professions available. If you have dual gathering professions you can consider to store raw materials on that character and then send them off to the alts with crafting professions when needed. Last but not least pick an alt responsible for general crapola. Every now and then you come across an item that's interesting but not part of a specific crafting profession, that's where the 'crapola' alt comes in (hearts of darkness come to mind).
Got your assignments? Yes? Write them down... not in any orderly fashion, don't worry about that. Scribble them on your desk for all I care, the fact that you're scribbling them down in the first place will help you remember.
Now, we have alts, we have bankspace, we have bags, and we have a assigments.
The next time you go questing and your bags are full you simply follow these steps for each item you find:
1. Can I use it now? Use it!
2. Can I send it to an assigned alt and use it later? Send it!
3. Can't use it now? Can't use it later? Sell it!
Stop thinking about what to do with those things, use, send, sell the second you hit town. Let your alts worry about sorting out what comes in.
The last and final stage of Inventory management is dealing with all that junk you've been sending all over the place. I do my inventory management on fridays (no idea why) but you can do it on an incidental basis if you like. Just do it before your mailbox timer runs out otherwise it'll go straight back to the character who sent it in the first place.
I have a simple 2 stack policy on items. I will keep no more than 2 stacks or two items of the same kind. Two stacks are enough to supply an immediate (crafting) need. Anything else gets sold by the alt responsible for the product (that way you know what happened to that ore you sold).
The only exceptions to this rule is if you're stockpiling stuff for powerlevelling something or anticipate that you can sell it for a nice profit somewhere further down the line.
Not sure what to do with what you found? Send it to the crapola alt, that should be the only alt with any real bank-space issues and yes, you will have to sort through the crapola and decide what to do with it sooner or later.
That's all there is to it, the length of this blogpost belies its simplicity but it's a simple system with very few drawbacks.
So let's recap:
1. Make alts
2. Buy (Netherweave) bags and all bankslots on each alt
3. Assign materials to the alts (i.e. all ores/bars to the paladin)
4. Use, Send, Sell after you're done questing
5. On regular intervals (a week, two weeks) clean your alts mailbox keeping 2 stacks of each mat in total or two items of the same type (make exceptions if needed)
What you gain is an overview of where your stuff is and a general indication of how much of it you have but more importantly you can clean your bags out after you're done questing without having to do any inventory management at that time because you can simply send off whatever you have to the correct alts.
Incidentally you also build up enough stock to supply your crafting needs rather than having to buy it from the AH. Especially on low-pop servers a lot of items are simply not available on the AH when you need them... there's nothing more frustrating than being 1 mat short of what you want.
There's other ways to manage inventory... possibly better. But this way works for me so feel free to use it and modify it to suit your own needs.