if I control Shrine of Boundless Growth
I cast doubling season
do I put one or two counters on the shrine?
if I control Shrine of Boundless Growth
I cast doubling season
do I put one or two counters on the shrine?
One. The Shrine's ability triggers and resolves before Doubling Season even comes into play.
By the by, if you're going to use any of the Shrines with Doubling Season, I suggest Shrine of Loyal Legions.
Fluttershy is best pony.