Neville came to the rescue of lead characters Harry Potter, Ron Weasley and Hermione Granger in Deathly Hallows: Part 2 and Lewis said that he was happy that all his scenes made the final cut.
He told Digital Spy at the Empire Awards 2012: "You have four different stages. Is it going to be in the book? Is it going to be in the script? Are we going to shoot it? Is it going to be in the final cut? You just never know until you turn up on the night.
"I was so lucky David Yates did me a tremendous service there... [and] kept all the bits in that we shot. I was proud of it. As an actor, I'm quite self-conscious... I sit in the cinema with the wonder of hindsight and I'll say, 'I would have done that different'. [But ] on the whole, I was happy with it."
Bonnie Wright, who played Ginny Weasley in the movies, revealed that she is looking forward to doing the Harry Potter studio tour soon.
"Obviously I spent all my time on the set, so I've seen it many times, [but] it will be exciting for the public," Wright said.
When asked about the 31-disc Harry Potter set which is being released in September, she said: "Oh my God! What will be on there? I don't know what's on there."
The final Harry Potter film won two Jameson Empire Awards at Sunday night's ceremony - 'Best Film' and 'Best Director' for Yates.
The film also won nominations in the 'Jameson Best Actor' category for Daniel Radcliffe, plus 'Best Female Newcomer' for Bonnie Wright and in 'The Art of 3D' category.
> Harry Potter, Twilight, Narnia, Eragon: Teen literature at the movies
Additional reporting by Simon Reynolds
Watch Digital Spy's interviews with Matthew Lewis and Bonnie Wright below: