It seems to me that there are 3 really important elements in good council estate preaching:
1) Being Christ centred,
pointing people to Jesus in our sermons. I based this on the assumptions that
a) All the Bible points to Jesus,
b) That he is our Lord and we are supposed to be glorifying him.
c) This approach avoids just teaching good morals.
2) Explaining the Text,
Breaking down the text into bite sized chunks, reading out these chunks, explaining these chunks. I base this on the following assumption:
a) In general there has not been a lot of Bible teaching on council estates.
b) By focusing more on the text, than on my own personal speeches, I am allowing (for want of a better term) more opportunity for the Holy Spirit to work through the words that he has already breathed out thousands of years ago.
3) Preaching to heart issues,
Bryan Chapell talks about the FCF (Fallen Condition Focus), the idea is that each passage in the Bible speaks to some aspect of our fallen human nature. If we know people well, then we can show how a particular bible passage speaks to a common problem that we face in life.
It seems to me that this approach could be taken by both indigenous (born and raised on an estate), and non-indigenous (middle class cross cultural missionaries) and be succesful. For example, if a posh city banker came to our church to preach, I expect that at first some people might wonder, "What can he tell me?" but if he did the above, then I think we would see the following results:
1) Someone thinking, "Wow! This bloke knows me, he's talking my own personal struggles I go through each day, I wanna hear more ..."
2) Someone thinking, "So that's what that verse means, that's interesting....."
3) Someone thinking, "Wow! Jesus is amazing, I really wanna know Jesus more....."