In tournaments, my trick not to get a long waiting-line for the spa: ultimate any and all 10% and 15% dragon the first time you encounter him. It saves you lots, and lots of time in the tournament, it saves you a very long waiting line for the spa (plus your dragons are available for other rounds) and it saves you lots and lots of frustration on each losing rond...
I have almost 350 unique dragons, lots of Champions, Triple-colors, 6 Diamond(hybrids), so for me usually it's just 2 or 3 rounds I need to ult, all other battles have atleast 25% chance - tho last time a 35%-Dragon gave me a hard time... lost atleast 10 times... And the last round, I only ultimate if I run out of time.
This tactic has made me win every tournament since October 2014.