As we teach our children to be gamemasters we are also teaching them how to handle treasure. In doing so we have taught them some tricks about magical treasure.
1) Don't give out powerful magical items right away. This is hard for kids, or even first time GMs, because they want to be powerful right away. Magic items need to fit the level of power the characters are facing, otherwise everything will fall to quickly before them and won't be as fun.
2) Try not to put too many random items in. That sounds odd, especially since treasure is supposed to be random, but we mean like the big ticket items. If no one in the group uses halberds, don't put in a halberd +2, make it a weapon the party uses. Weapons are so rare, anyway, why make it a big disappointment that it isn't a weapon they can use.
3) Try your best to make sure everyone gets magic items. Now, don't give a magic item to every player every adventure, but make sure you aren't giving magic items out that only one or two players can use. Make sure to rotate and that everyone is equally equipped, at least most of the time.