The risk-reward element of exploring the wasteland in Fallout Shelter is pretty simple. The longer they're out exploring, the higher the probability of terrific loot. So let's increase that probability.
It's called a negative time glitch and, as YouTuber Gym Leader Matt explains, it basically cons Fallout Shelter into thinking your dweller has been exploring for decades by tricking the game around the time loot is about to drop.
It's not 100% reliable, but when it comes off you're basically guaranteed to get legendary gear. What you need is a dweller who has been exploring for at least a couple of hours.
The trick revolves around sending a bunch of dwellers out right when the game is about to give an item to your veteran explorer. The video explains.
Pretty neat trick. You'd imagine that Bethesda will patch this sooner rather than later, but given that it works on all platforms and is a little tricky to execute it might be something that you can use for a while.