the replicator button... use it to sell stuff you dont need.
# sell all the hypo, shield and etc... you can get them cheap in DS9.
# sell every white item you are not going to equip soon. but keep those ppl need for crafting, check the crafting faq to see what to keep. too many to list here, a example would be all instance of impulse engine mk iv, vi.
# sell every 56% food and every 64% food not sold in DS9, all the other food that remains, check on the AH to see if they sell, else find the tribble faq and check yourself.
# keep going back to earthdock to drop of the crafting mats, it should only eat up about (3x3=9) slot, as the drop changes across zone.