Looking after a turfed lawn?

Question:Over the winter, my grass vanished from my back garden, except for a few small patches here and there. It had survived the previous winter, so this was something of a mystery to us!

We have been advised that our soil is clay based and I decided to completely returf to get our grass back. What kind of perperation should I do first before laying turf and what kind of after care should I do? Will it need a lot of attention earlier on instead of later?

Any help appreciated.

Answers:
either find a grass that grows in clay, or bring in fill dirt then plant grass. grass needs something to root into.