If you are a crafter with multiple or all crafts leveled you have to actually organize your inventory, not just stuff everything in there.

Weaver: Keep only your threads on hand. Anything that turns into thread, do it and keep a stack of each type of thread around. Don't keep cloth (except felt) since you can use your threads to make the exact amount of cloth you need for a recipe.
Goldsmith: Ores into ingots, keep a stack of each. Lower level gemstones don't really need to be kept on hand, but keep the higher level ones.
Armorer/Blacksmith: Ores into ingots, keep the ingots. Plates, rivets, rings, etc. can be made on an as needed basis.
Carpenter: Logs into lumber. Keep higher level branches around, but no need to stockpile the lower level ones.
Leatherworker: Skins into leather, same as above.
Alchemy and cooking are a bit harder to control. For these, just keep on hand the mats you use for your most frequent recipes. There's lots of things that you could keep on hand, but don't really need to.

You shouldn't have too much of an inventory issue. You just have to stop every once in a while and consolidate any drops or gathered things into what you're actually stacking and storing.