When a potion is found in your campaigns, are the bottles labeled as the the contents (accurate or otherwise)? Are there common symbols use for healing, invisibility and the like? Do all healing potions have the same color (and can the experienced alchemist identify potions by color and or smell alone?)
I'm always on the fence as to whether or not the party should be able to quickly ID the more common potions they find in their adventures.
How do you handle potions?