Okay I get that I'm totally showing off here but oh my goodness the bread has gone from good to amazing!
I've been making the sourdough for a year now and only just recently am I feeling like I understand it. Well I'm not sure I understand it exactly, but I've made a few changes which are working really well.
It's all thanks to this fantastic book (which I may just have to buy).
The bread has lovely (bubbly) crusts on it now which I think may be from the water sprayed on before baking, to be honest though it could be something else.