Here is my idea for crates:
Open them now, sell and the materials and follower upgrades.
Vendor all the non transmogable gear, like rings, necks, trinkets.
DE/Vendor bop blue gear.
Sell WoD epics because they can still bring you some gold.
And for the transmog items, sort them by type and pach in grops of 12, (cloth, leather, mail, plate to a respected classes, and all weapons except wands to a warrior, and wands to a warlock for exmaple).
And then you can mail them to your charactes. So 12 items will fill up one mail slot, and you are safe for 2 months. After that you have to do it again. But with his (time consuming, but then again what else to do in wod?
) technique, you can sell double items, and save some more spaces and make some money now.
At least that's what I'll do soon.