Harris said as previous Harry Potter films had mainly focused on kids doing magic,
Order of the Phoenix was an opportunity to showcase the full power of the heavy-weight wizards.
"I wanted to bring out more of their inner power," he said.
"So I gave the actors the fundamental choreography which was basically a combination of ballet, Kung fu and fencing type moves. I then encouraged them to personalise their own moves with the wand befitting their characters. So Jason Isaacs (Lucius Malfoy) used his wand completely differently to Gary Oldman (Sirius Black)."
Harris said he couldn't create a specific movement for a specific spell as many of the spells had already been executed in past films with little movement behind them.
"So what I did was create a set of positions for attack and defence," he said. "From there any spell could be launched or defended. From those positions I built up the choreography."
Helena Bonham Carter perforated Matthew Lewis' eardrum
In one scene Helena Bonham Carter (Bellatrix) held Matthew Lewis (Neville Longbottom) hostage but took things a little too far.
"I remember Helena turned to the director and said 'wouldn't it be quite fitting and sinister if she started to really enjoy torturing him?'" said Lewis.
"Then she started playing with her wand before sticking the tip in my ear teasingly. There were lots of explosions going off around us and suddenly it went straight into my ear about an inch. It actually ruptured my eardrum and hurt like hell - I couldn't hear anything for a week but it looked great on camera."
Bonham Carter admitted there was pain - and blood.
"Well, torture happens," she said afterwards. "Sorry! Oops! I think I took my sadism a bit too literally."
Harris said he caught up with Lewis earlier this year when they both appeared at the Celebration of Harry Potter event at Universal Studios in Orlando Florida. Harris performed a wand coaching class in front of 6000 people and Lewis posed with fans.
"I'm happy to report Matthew is now fine and can hear perfectly well!" Harris confirms.
It took two months to choreograph the combat scenes
All in all it took two months of preparation and rehearsals to get the combat scenes just right. Harris also worked extensively with body and stunt doubles who filled in for actors at rehearsal when moves were being perfected.
"Daniel Radcliffe was in so many scenes that he was much less available for rehearsals compared to other actors," said Harris.
"At one point we didn't shoot any wand combat scenes with him for about a month. And then suddenly he'd pop up again."
Gary Oldman was the best wandsman
Harris felt all the actors were completely focused and committed to getting their wand techniques right.
"However the magic and power of the wand particularly came to life in the hands of Gary Oldman," he said.
"Gary is such an inventive actor, he was just fantastic. The element which really made the duels so exciting was the power of intent behind each wand movement. Gary certainly brought a lot of intent to his scenes."
Devon Murray broke the most wands on set
According to Radcliffe, Devon Murray, who played Seamus Finnegan, held the cast record for breaking the most wands on set - 10 in all - during filming.
"The wands got handled an awful lot although I didn't see anyone actually break a wand while I was around," said Harris.
"But we did tend to throw them up a lot into the air and try to catch them, I was constantly doing it. We were always using different wands, everyone had a rehearsal wand plus an on-screen wand."
The kiss between Harry and Cho Chang was done 30 times
Radcliffe (Harry Potter) said he chewed gum for hours in preparation for his big kissing scene with Katie Leung who played Cho Chang. However getting the smooch right took quite a while.
"Katie and I were a bit awkward and nervous at first, but once we got into it, it was fine - even if we had to do it about 30 times!" he said.
Leung said in order to relax she listened to Coldplay, however it did little to settle her nerves. "Before I did the scene everyone kept coming up to me and asking if I was looking forward to it. It got me really, really nervous and I was having sleepless nights over it," she said.
"But when I actually did the scene it went very well and Dan was great. He said he was nervous as well. But the director [David Yates] was really cool about it too. Dan and I are great friends now however it was a bit strange to have to kiss him for hours at a time."
Katie received hate mail from jealous fans following the film, but has since recovered.
The Ministry of Magic was an explosion threat
Although the Ministry of Magic took 22 weeks to construct, it was actually only on screen for less than 10 minutes.
Cast members weren't allowed to have their mobile phones on them while filming there as the ministry was rigged to explode. There were fears that the phones could trigger an explosion.
20,000 people auditioned for the part of Luna Lovegood
Casting for the part of Luna Lovegood was like finding a needle in a haystack. Producer David Barron says the casting director initially saw about 5000 people in schools, but had no luck. They then thought they would hold an open casting call.
"We thought we may end up with 5000 or 6000 people," Barron aid. "But we had 15,000 people show up. Then there were 400 put on tape because the casting director thought they had some kind of promise."
One of those girls was Evanna Lynch who got the part. Evanna was well prepared - she'd been a massive Harry Potter fan since the age of eight.
