Hi, I'm new on the forum here (and new to the UK).
I'm an identical twin, and I've just had a baby of my own, so I have new found respect for my parents in how much work it would have been to raise 2 babies when they were just expecting 1. 1 is hard work!
I think it's important to treat your twin girls as individuals. Ask them different questions, read them different books, don't always compare them. Try to treat them like siblings, not like twins. I feel special being a twin, but there were some major down-sides growing up. Always being compared was one of them.