As a 5e GM, I find myself continually under-rewarding my players, with physical treasure that is. I can't seem to find ways to lay on more loot. If it's my GMing style, it's wholly unintentional. At the same time, I'm not sure my players want to keep accounts of coinage. Anybody care to share tips for simply and easily remembering to give out meaningful physical rewards without having enemies explode into coins like in Scott Pilgrim, or unrealistically dropping just the right style of item for the party's particular set of builds?
Here are some ideas that have worked for me:
Monsters Have Homes
These things live some where. They have stuff stored there. For a big thing like a cyclops, it may be some sheep, some barrels of wine, and a few pretty bits of oversized jewelry. For a band of orcs, the chief is going to have a hoard stashed somewhere "safe" that he can use to reward his warriors and bribe his neighbors. A gelatinous cube will have non-digested bits floating around inside it (and other critters might also have undigested bits lodged in their bellies, though if you do this today, you might have to hint to the possibility to the players or they will likely miss it.) What sorts of things do the monsters collect, either purposefully or accidentally? What sort of things are needed around the home that would be decorated or made from precious metals (like all those cauldrons and tripods everyone is gifting around in The Odyssey? That's your treasure.
So that answers the "why" and the "how" of treasure, now we'll look at the "what."
Treasure as Plot
I can't remember which blogger said that the sole time you have the full attention of everyone at the table is when you're describing the loot. Take advantage of this to deliver important exposition. It's never a longsword +1, but a sword of Vekna's crack siege corps the Flaming Gauntlet, or a bride gift between the elven Princess of Andiel and the human Sultan of Kyma, or the work of the famed dwarven smith Oran, son of Abon (and that means, assuming it's not a forgery, that there should be a key hidden inside it somewhere).
This sort of thing is even easier to do with jewelry, books (remember, a blank book is worth 25 gp, more than a longsword), scientific equipment (a spyglass is worth 1,000 gp), clothing, etc. And don't overlook the possibility in simple coinage. That the assassins recently took a huge payday in Aqualonian florins could be a clue you want your players to pick up on. If you make a big deal pointing it out, they'll almost certainly get the hint.
In short, if you've got some ideas about what's next, point the PCs to it with the treasure. If there's something you want them to know, tell it through treasure.
Worth More than its Weight in Gold
This is a strong tool to tie your players to the setting. Once they recognize this relationship, they'll look to exploit it (let them) and seek other opportunities to do so (encourage them). Now they'll be asking you for exposition instead of glazing over while you dump it on the table.
You can use this sort of thing to help the PCs get the magic goodies they desire without it just happening to be in the first hoard they loot. Let them find out that the thing they want is owned/manufactured/guarded by such-and-such a person. This could be a sage with a large collection of artifacts, or a wizard of terrible power and poor people skills, or a naga under a sacred duty. Then make it clear to the players that they won't be able to buy the item with simple coinage. They must find something in exchange of equal or greater value to the being that owns the desired magic item. Thus, the sage might trade it if you can add to his collection of complete dwarven chess-sets dated to the Interregnum; the wizard desires the materials needed to complete the enchantment on his Staff of the Magi; the naga will exchange the magical item for an item of evil power that needs to be hidden from the world and kept safe. This feels far more organic than the item just happening to show up in a hoard and can also be used to create quests the players are eager to pursue.