I've got an offer from UEA for English. Since this is all personal statement fodder you're talking about, I'll break down the content of my statement. Total: 640 words.
337 words about how I bloody love books. I love this book, I love that book, I've been studying these books and talking about this. I talked about a range of authors - started off with a John Green quote, mentioned Salinger and Kafka, referenced The Hungry Caterpillar for a laugh and talked about the texts I studied for A2 coursework and what I found interesting about them (I think mentioning that I chose one of the texts myself was a worthwhile thing).
212 words about my other subjects and how they relate (skills-wise) back to English, about my EPQ, about my future ambitions and my feelings about how bloody great books are, if I didn't mention it already.
142 words on Duke of Edinburgh and my conclusion.
English isn't medicine, you can't get an internship as a published novelist (or even at a publisher under the age of 18). It seems to me that a pretty good way of getting the attention of whoever reads these things is to really, emphatically, skilfully and - most importantly - genuinely portray your passion for literature - all literature. Demonstrate that you are a student who is deeply interested in everything an English course has to offer. So in terms of extracurriculars? Read. Read a lot, read broadly, follow your passions. That last one is key - you want to portray genuine interest, not come off as a box-ticker. Talk about what interests you outside of what you have studied and let your passion come across through your words.
One tip I heard from a member of Royal Holloway's English department at an open day was that, at interviews, too many students will have written that they have developed a real interest in Jane Austen after reading Pride and Prejudice for school but, when asked, haven't actually read any other novels of hers, or something like that. Don't be that person - talk about literature that genuinely excites you. Breadth is important and I'm sure appreciation for the classics is a plus, but don't fake it.
man, i can write a lot when i don't feel like going to bed. hope that helps!