Just make funny :-）
can u add some item that can be throwing?
example ：
Cleaver [ hitting the target will cause it to bleed (team fortress 2 ? XD) ]
Hatchet [more range damage]
Sandwich snowball [stuff something into the snowball will get different effect for that]
Watermelon [just the vanilla one in the field ,player can use shift+right to click lift it up and throw it ]
Bottled magma [throw on hit to generate flow lava(it will disappear soon) ]
Record [just the vanilla too, powerful dart because it's hard to get a simple way to get records,also different record have special effect (throw into the jukebox can also play it , cool)]
Book [( Knowledge is power!! )Get different throwing effects by enchanting. ]
Skull [maybe a little tracking effect?]
Playing cards [a set of playing cards , the throwing weapon based on luck, the Joker is the best attack of them]
Detonation pickaxe[Mmmm ..just funny and funny]

Closing as GrimPack is no longer maintained.

This seems interesting ideas some of them are definitely cool. Right now I don't have the time to implement these but I might be able to in the future but no promises.