This is a tricky balance.
Obviously the point is to get Quest for Ula's Temple in play (ideally right from the get-go), then quickly get three counters on it and play big blue beatsticks until the opponent succumbs. But the devil's in the details, because it's not quite that simple.
Fortunately, QfUT has a CMC of 1, so if you find it early, you can play it early. But what about after that? You can't just load your deck up with fatties or you'll likely lose out to damage before you ever get to pop off your own threats. You can't play a ton of counters and other trickery because QfUT requires a pretty steady flow of creatures in your library to get counters. But you can't really just load up on ALL creatures; you likely need some deck manipulation and drawing to keep things moving, and SOME countering can be critical to keep the big threats down and keep your own threats alive. So we need a goodly amount of creatures--a decent number of them fatties that can be dropped by a loaded QfUT--along with some card draw, deck manipulation (to get your good stuff to the top of the library), and ideally some defense in the form of defensive creatures and/or counters to keep you alive.
Like I said, it's a tricky balance. But there are cards that help in multiple areas:
Augury Owl and Sage of Epityr help with chump blocking, but of course they do much more than that by sorting around the top few cards of your deck. Combined with Serum Visions, Foresee, and Halimar Depths, they help you get creatures to the top to load up QfUT, and then pull fatties up to play for free later. Tezzeret's Gambit can then draw more cards out and give you a fresh top of the deck to work with.
Speaking of Tezzeret's Gambit, note that it also proliferates...your quest counters on Quest for Ula's Temple! So does Fuel for the Cause (while also countering key spells) and Clockspinning. Even just triggering one and getting QfUT triggered one turn early can be HUGE.
Then there's the fatties themselves. Inkwell Leviathan is almost enough to win the game by itself. It also happens to have the same CMC as Grozoth, which can dig for it a couple different ways. Deep-Sea Kraken isn't quite as huge, but it has an alternate way to sneak into play on the cheap thanks to suspend. On the other end of the spectrum, Stormtide Leviathan and Lorthos are all but game-enders if they resolve and live for a turn or two.
There's a couple other creatures too. Fog Bank is one of the best blockers in the game and can buy you critical time early on to get things in place. Ætherplasm presents an interesting alternate strategy for getting out a fattie if you're in a bind, and Quicksilver Amulet is a little slow, but perhaps more easily repeatable. Either one can greatly speed things up if you just can't get Quest going.
More of the same in the sideboard, with some more defense, control, deck manipulation, and of course, more fatties which can be brought in vs. certain decks. Also Mindshrieker is, at worst, a flying chump blocker that can get big with a little luck. At best, it's an alternate win con, allowing you to reveal your own massive creatures from your deck and swoop in with a flying beater. He's even better if your opponent plays a lot of expensive spells too!
How does this look? Any tips and tricks (or likes!) would be greatly appreciated. Thanks!