Try using an Updraft on your attacking Polar Kraken or Leviathan. A suddenly flying 11/11 or 10/10 creature with trample tends to send opponents scurrying for cover. You won't have to sacrifice land for long if you can attack just once or twice with a flying Kraken or Leviathan!

My favorite use of Updraft is with an Elder Land Wurm, which is a 5/5 trampler who cannot attack unless it has been declared as a blocker. Most opponents will not send small ground creatures in an attack if I have the Elder Land Wurm untapped because they do not want to give it the ability to attack. However, I can cast the Updraft on the Elder Land Wurm and block one of my opponents flyers—a nasty surprise in itself. In fact, in one game I got to play this combo twice, thanks to a Miraculous Recovery and a Relearn. Ulrich still maintains that playing that particular combo twice in one game was a bit excessive.
—Helva

I might add that Updraft can also be used by you red and black players. Imagine the fun of Updrafting an opponents Craw Wurm or Craw Giant, then Thunderbolting it! You could also use it to give your Krovikan Vampire some new targets. Or you could use it to save a key creature just before a big Earthquake.
—Ulrich