I have opted for some slower, permanent sources of spell doubling
For a cost of 2WW, Luminous Broodmoth is well worth getting out as early as you can, providing protection through recursion and making your heaviest hitters that much more evasive
This is where a lot of the value in the set resides, with cards like Enduring Innocence, Meathook Massacre II, Kaito, Bane of Nightmares, and all of the Verge lands (Gloomlake Verge, Floodfarm Verge, Blazemire Verge, Thornspire Verge, and Hushwood Verge)
Idol of Oblivion If you have a way to generate tokens (which, in Magic, are legion), Idol of Oblivion becomes a solid once-per-turn draw engine
Even still, the abilities that you immediately have access to with this planeswalker arent anything to write home about