In Skyrim, you are free to draw a new weapon without sheathing or dropping what you currently have in your hands—it just magically returns to your inventory. I’d like to see a mod with similar mechanics to “drop lit torch” so that if you don’t sheath your current weapon before you draw a new one, your weapon drops to the ground. This would increase the difficulty of combat and make it more strategic as there would be a cost associated with not taking the time to properly sheath a weapon. The biggest downside would probably be finding your weapon after (or during) the battle, and the hassle of having to favorite it again.
This idea was inspired by a combat mechanic in D&D. In D&D, drawing and sheathing weapons are considered actions that take time. It is possible to draw a weapon as a free action—meaning it doesn’t interfere with your ability to do other actions in the combat round—but in that circumstance you are typically forced to drop whatever you were holding.