I'm an Iranian girl. The important thing to consider is the values that matter to them which have a huge dependence on the family in which they were raised. Normally, In Iran you can see three groups of people; the religious, the half religious and the none-religious which is far more frequent in the UK. As regards the religious, do not really try to approach them, that's quite pointless. But about the other groups, I should say, you don't really need anything special in terms of manner but in terms of other factors, there is a really obvious logic behind why Iranian girls prefer rich guys which is living in the UK is really money-consuming and expensive for Iranians (because of the currency and other financial issues), so logically they prefer those at the same level as theirs.
After all they're not from the outer space, just like other girls, be nice and kind to them, have a sense of humor and be good looking. And another thing, most of them don't really like it when you act like a pervert at first sight (just in case).