Is there a way to use an item (e.g. a mushroom to heal) in Terraria without placing it on the hotbar first? I know about the "use health potion" shortcut but I wonder if there's a general way that works for any item type (e.g. a single buff potion).
Use H for health potion, M for mana potion and B for all buff potions. It will use the first item available, starting from the hotbar and moving from left to right, top to bottom. Except with Buffs, which it will drink all available (though not entire stack, only one per stack)
So if you have an Ironskin Potion and Spelunker Potion and use B, it will drink both Ironskin potion and Spelunker Potion.
If you have Lesser Health Potion before your Greater Health Potion, it will use LHP first. Learned this one the hard way while fighting Destroyer.