When you are ready to make a loaf here is what to do:
Take 100ml of starter and add 250g bread flour and 275ml of warm water, mix with hands and leave overnight.
Next morning add 300g bread flour 1 tbsp oil and 10g salt, mix and kneed for 10 minutes. Leave for most of the day to rise, it will take longer than an loaf made with yeast.
When the dough has risen to about twice its size knock it down and leave again to prove this time for about 2-3 hours, again it should be double size.
Then place the dough on a heated floured tray into an oven preheated to 230C. After 15 minutes reduce the heat to 200C and bake for a further 25 minutes.
Here it is: