Diadems..

The odds of getting the perfect Diadem are incredibly low. I've gambled probably a half billion on circs & coronets and never gotten a really good one, just some basic 2/20s, and my 'sin's which is 2/20 15@res. A blue 3cold 20fcr and a 3light 20fcr, both of which Larzuk, who is a jerk, gave me 1 socket on >_< No 3os 30frw either. Keep in mind, if you do gamble a nice rare circ or Coronet, it can be up'd to a Tiara, then up'd again to a Diadem.

You may want to consider rerolling pelts, since these can't be gambled. An Earth Spirit and Sky Spirit can roll any affix, it's the same thing with QLvl being high enough that you can infinitely reroll them and they retain the ability to roll +2 druid (and other high level affixes). The only thing is that they can't roll the highest level +life mod from the regular affix pool - but they CAN roll it from the pelt affix pool, where it's a lower level requirement. So they can get the highest +life, but there's a lower chance of it. For any affix from any pool, reroll a Dream Spirit.