I'm running 5e in a homebrewed setting and my players are in the middle of a fairly big plot thread, helping to break the siege of a Dwarven Hold. After they accomplish that, the plan is to have them journey to the other side of the mountains to investigate the possible disappearance of an astronomer/astrologer whom the Player's patron has lost touch with.

Here's the thing: I plan to use the adventure to introduce some magic items as rewards for the party. They're lvl 4 now, lvl 5 next session and likely lvl 6-7 by the time they're done with the trip to the astronomer's observatory. I plan to introduce several player-specific magic items (like the Belt of Protection for the Druid that works when she's using Wild Shape) as 'useless trinkets' the mad wizard has lying around. I'd also like to toss in a couple of plot-hook types of things that the PCs can choose to quest for or that will motivate them to go off and do other things than run around and be agents of the king (that's cool early on but I don't want it to get dull).

What I'm looking for are some ideas for magic items that are not necessarily super-powerful but will be something that will spark another adventure.

Also, there is supposed to be a fairly sizable horde of loot several days from the observatory (unrelated to it completely). Other than simply having money and gems, what sorts of things might I toss in THERE that might spark a new quest line or adventure? (The horde was abandoned by a group of merchants intent on traveling to the Dwarf Hold to trade for Dwarven stuff but they were attacked and had to abandon their heavy loot in order to try to escape).

Thanks in advance.

I like using consumable magic items. It adds a level of resource management giving the PC more decision to make. Plus if the item is super-powerful it won't destroy the balance of the campaign because it's a consumable, after it's used up its gone. Spell Scrolls, Potions, Dust of Disappearance, and Chimes of Opening are a good place to start but you can also make your own, or if you think a magic item would be interesting to give to the party but you're worried just think of a way to turn it into a consumable.

Splitting magic items in half can help encourage the PCs to go looking for the other half. A powerful spell scroll but it's torn in two, where's the other half? A crystal ball shattered into 3 pieces, a sword blade missing its hilt, this sort of thing serves as a good hook to get the PCs interested in tracking down the item's other half.

Quote from VorpalCoffeeCup >>

I like using consumable magic items. It adds a level of resource management giving the PC more decision to make. Plus if the item is super-powerful it won't destroy the balance of the campaign because it's a consumable, after it's used up its gone. Spell Scrolls, Potions, Dust of Disappearance, and Chimes of Opening are a good place to start but you can also make your own, or if you think a magic item would be interesting to give to the party but you're worried just think of a way to turn it into a consumable.

Splitting magic items in half can help encourage the PCs to go looking for the other half. A powerful spell scroll but it's torn in two, where's the other half? A crystal ball shattered into 3 pieces, a sword blade missing its hilt, this sort of thing serves as a good hook to get the PCs interested in tracking down the item's other half.

I like the idea of partial items! Never thought of that. The consumable idea is good too. Thanks!

Glad I could help. When using partial magic items remember to make sure that even a partial item has a benefit. Players are very instant-gratification minded, and will want to be rewarded, giving them an item that's useless until reunited with it's mate will leave a bad taste in the player's mouth.

Some good dungeon/adventure design is to give the first half of the item an ability that allows you to solve the next dungeon in a gimmicky way. For example a wand that lets you cast Enlarge/Reduce, the wand has been cut in half and the part they have only casts Reduce, the dungeon holding the second half has puzzles that are solved using the Reduce ability. Because anything your carrying returns to normal size when you drop it you could create some really interesting puzzles based on shrinking items taking them to new locations and dropping them.

Quote from VorpalCoffeeCup >>

Glad I could help. When using partial magic items remember to make sure that even a partial item has a benefit. Players are very instant-gratification minded, and will want to be rewarded, giving them an item that's useless until reunited with it's mate will leave a bad taste in the player's mouth.

Some good dungeon/adventure design is to give the first half of the item an ability that allows you to solve the next dungeon in a gimmicky way. For example a wand that lets you cast Enlarge/Reduce, the wand has been cut in half and the part they have only casts Reduce, the dungeon holding the second half has puzzles that are solved using the Reduce ability. Because anything your carrying returns to normal size when you drop it you could create some really interesting puzzles based on shrinking items taking them to new locations and dropping them.

 And in the case of the sword, you could have them find the hilt, and the hilt becomes a key when inserted into a specific opening in a dungeon that get you access to the blade.