You just finished an arduous and long fight with a huge group of enemies and your entire party is reeling. In Baldur's Gate 3, you have a few options--each person takes a swig of a health potion, a healer gets to work, or you rest. But if you want to save your potions instead of having everyone stockpile and waste their own, you can just throw them at the ground and heal everybody.
It turns out that splashing the potion turns it into a healing AoE. Don't ask me how it works. Do your toes suck up the liquid? Does the magical aura of a potion have the same effects as drinking it? Is ingesting even necessary? Too many questions, and not enough time. The point is, one potion can heal four, so don't waste four potions.
There is a catch to this strategy, however. You need to throw the potion at the ground. Not at your party directly. There are a couple of good reasons for this. A) they can dodge the potion because it registers as an attack, meaning you'll waste a vial and not heal anybody, and B) you can kill them. Yep, the force of a healing potion smashing against the face of a party member with low HP can ironically wipe them out.
"Just to clarify, do not throw the potion AT your companions, throw it on the ground besides them," foul_frank2 warned other commenters. "I killed my main character with a greater healing pot critical strike in the side of the head."
The upside to that is you could probably use a health potion to kill an enemy on low HP, really rubbing salt in the wound. You'd waste a health potion, of course, but is it truly a waste in the face of unbelievably petty spite?
This doesn't just apply to health potions (though some, like resist poison, have caps or flat out don't work). Take the basilisk oil... just be careful. It comes with a few risks of its own.
"I found some... statues," draeath said. "I threw some basilisk's oil down (removes petrify). It unstatued them... and pissed off the local Beholder in the process [...] I barely survived."
If you try to use this tactic in combat, you also need to make sure there aren't any enemies nearby. Your healing splash might catch all your clustered party members, but if enemies are within hacking and slashing range, they'll benefit too. Basically, throw your health potions at the ground, but not near enemies. And definitely not at your companions' heads.