Bottled Water

Nearly every potion and every flask starts here, so the real question is never whether to make it but where. It needs water nearby, and a sink counts as water, so putting a sink in the corner of your crafting room saves you the walk to a pond for the rest of the world. You only have to be close to it, not standing in it.

Do not think of it as a healing item. It restores a small amount and then locks you out of potions for a long stretch afterward, which in a fight is the same as being unable to heal at all. Drink one only when you are out of combat and out of anything better.

Crafting does not lower the water level, so one puddle supplies you forever. Drinking it does not hand the bottle back, and there is no way to pour it out onto a block the way a bucket works, so it only ever moves in one direction.