"Well, now we know what to do next time I can't manage a spell," ... "threaten me with a dragon."
--Harry Potter (GF20)
After Professor Moody/Barty Crouch Jr. gives Harry some hints, he realizes that he can summon his broomstick and use it to deal with dragons. Harry enlists Hermione’s help, and they skip lunch to practice the Summoning Charm in an empty classroom. At first, Harry struggles and has trouble concentrating. They each go to their respective afternoon classes, but Harry spends most of that time covertly practicing the Summoning Charm under the table. After dinner, Harry and Hermione reconvene in the empty classroom for more practice. They work on it there until shortly after midnight, when Peeves disrupts them and they hurry away before they can be caught out of bed. They resume their practice in the Gryffindor common room until Harry masters the spell at about 2:00 in the morning on the day of the first task (GF20).
The items Harry practices summoning include furniture, a heavy rune dictionary, and even Trevor, Neville’s toad. Harry is a little concerned that the greater distance he’ll face during the task will make it more difficult, but Hermione tells him it will work just fine as long as he focuses (GF20).