i think thats a very bad way to receive the idea of creativity with spells. if theres a spell that already does that, who cares? the idea that magic cannot be versatile (the entire point of having different magic spells) turns dnd into an A + B = C game, which is also entirely contrary to an open world roleplaying game. If you don't like the "door" to applying logic to dnd scenarios to come up with creative solutions, whats the point in playing the game? At that point you'd get the same thrill sitting in the corner rolling dice and seeing which two rolls are higher. It's already not the same as knock because it stated that the DM could have alternate rules apply, and a roll could be required. Which is entirely why we propose these creative scenarios in this game anyways, because there's a DM to make rulings that exist outside of RAW. Page one of the DMG addresses this. Just because there's a spell that already does it (a spell almost no one takes) is no reason to avoid creative thinking. Not trying to be hostile, just trying to make a point.

I have a "Paladin of Water" (paladin 6 / tomelock 3) with this cantrip.  I've used it to make stepping blocks across ponds and other water hazards, to form walls for cover and for short rests as the article describes, to create all manner of Tools for the various PCs' proficiencies to use, and to douse flames accidentally set by the party druids (Wall of Fire).  I tried drowning a target with controlled water, but the DM did veto that one as "beyond the power of a cantrip" (which is totally fair).  I haven't tried exploding a lock with flash-frozen water, but I have used the cantrip to freeze myself a key that perfectly fits the lock.

Combining this with a create bonfire for controlled boiling water is a new trick though!  Mwah-hah-hah!

Quote from eyeonball >>

5e does not allow GREASE to be set on fire, as prior editions did.

There's nothing that says it can't be ignited.

Speaking as someone that can pick locks, I don’t really agree with the whole “freezing” a lock open. A lot of those older locks would not give so easily. I am an avid user of this cantrips but I’d rather just shoot the look. You can still apply enough pressurized force thanks to this spell that it would cause it to pop open. A lot easier than freezing. 

Quote from Backcountry164 >>

 Knock is a second level spell that comes with a significant downside. Everyone nearby is alerted every time you use it. So you're suggesting there's no problem allowing a cantrip to do a better job than a second level spell?? I'll have to disagree with that. 

Eh, Knock is a guaranteed success (barring special anti-magic locks or such), whereas using this technique means it is entirely up to the DM if it is even feasible. HUGE difference in usage. And if you are using Knock, you are almost certainly either not concerned about being noticed (like, in one of the countless dungeons you may explore) or are ready for the risk because you know that's how the spell works. Or your character just doesn't care about stealth, that's always an option. The "downside" of Knock is rather situational whereas its power is not.

On the other hand, the downsides of not being guaranteed to even be able to break a lock open (and possibly just permanently jam it in a failure!) or even it be not possible on a given lock, Shape Water is hardly a replacement for Knock. More like a hopeful alternative.
Just because you can fill the lock with water and then freeze it doesn't mean it will have any more effect than just filling the lock with ice. The DM has the entire say on if it is possible to succeed or if they have to reach a very high DC (because they are trying to break open a lock with standard ice and no other special tools or setup). I would most likely rule "no" in my games, unless it was a particularly weak/old/etc. lock that would be just as easily smashed with a hammer. Then it's just letting them flavor how they destroy the thing.

However, and it is depressing that the author didn't think of this instead, that WOULD be a useful technique for preventing someone from opening the door! The guards can't fit, let alone turn, a key in a lock perfectly filled with ice. I guess, in theory, one might also unlock a door normally then use ice to hold it in the unlocked position, though I can't think of a great reasoning right off.

Sadly, the spell explicitly says it cannot freeze water with a creature within its area. Which I think is totally stupid and am already considering houseruling away that limit for my players (should they use it). I couldn't care less if that can lead to some OP shenanigans (only good reason I can even think of to not allow it), I enjoy seeing my players be interesting!

Sorcerer: I throw the contents of a waterskin in my opponent’s face, then use Quicken spell to cast Shape Water and cover his nose & mouth for 1 hour

I have used this cantrip a few times to create an ice bridge, and have used it to help a performance among other random things 

Couldn't you make an ice key

On Shape Water being used to affect other liquids. Blood and alcoholic drinks are not distinct liquids. Even a strong drink like whiskey contains about 30% water and blood plasma is like 90% water, so it is completely feasible if your DM allows it that you can use this spell to shape other liquids that contain water or at least the water contained within them.

Everyone's talking about smashing locks with this spell but no one's talking about the holy ice weapons you can make at will which sound far more awsome. It says in the rules that if an improvised weapon is shaped like regular weapons they can use those stats instead. I would love to play a character that can summon divine ice staffs at will through magic.

I'd allow a one-time hit and then it'd break. It might have the shape of a weapon, but ice is brittle (it'd also keep with the logic that holy water is a one-time use attack and it costs 25 gp per attack).  Holy water javelins and daggers could be fun.  I'd probably also rule with daggers that you could attack again with it on a miss (where a miss with a thrown flask just loses the water).  That'd be a nice low-level two-weapon fighting opener in a room of zombies...two dagger attacks doing dagger damage + 2d6 radiant each.  expensive though.

Whoa, HeathSmith, how cool!  (no pun intended)  I can totally see higher-level ("Gold? what's that for?") characters totally willing to throw some "holy ice daggers" to open a fight!

That's fair, even so the shape water cantrip is still a great way to increase the effectiveness of holy water afterall its costly so you want to get as much bang for your buck so turning it into throwable ice weapons is a good tactic to not only increase the damage but is also very thematic. Think about it: a Arctic Land Druid with a 1lvl dip in Cleric master of ice and scourge of the unnatural

my campaign passed through some spores and we utilized the cantrip to keep the spores from poisoning us, and later we used the spore infested water as a weapon and shield, nothing could touch it without getting poisoned!

The cantrip says you can shape, animate, and direct water for an affect that will last for an hour.

Can the shape water cantrip be used to animate a small sphere of water directed to remain centered about an enemies head thus starving the enemy of oxygen for an hour?