After you complete Professor Flitwick's mini-quest, the Charms room will become unlocked. Go inside and talk to him. He will call out spells that you need to cast on certain objects. If you pass and get an "Outstanding", it counts it in the Room Of Rewards. The order he calls the Charms in is as follows:
1. Wingardium Leviosa: Use it on a bench.
2. Reducto: Use it on a statue of a bird.
3. Reparo: Use it on the pile of broken dishes.
4. Accio: Use it on a rope near the fireplace.
5. Depulso: Use it on a chair.
6. Accio: Use it on a rope near the fireplace.
7. Incendio: Use it on the plaque.
8. Reducto: Use it on a statue of a bird.
9. Reparo: Use it on the pile of broken dishes.
10. Wingardium Leviosa: Use it on a bench.