Mail is the most common by far. Open the console with ` and play the brain dance game to get a password, then you can spawn items as you want.
Spawning in items isn't the natural flow. Spawn rates are custom set per item.
I'll look into balancing that data out a bit more so there is a bit more flare to what is dropped without pop-ups, but a small feeling I have is when we add more content that problem will slowly fix itself as well. Still good to look at!