Knead it until you pull it apart and you can see it's really thin. If it tears before it gets thin it needs more kneading (my mate does a no knead method. You only fold the dough a few times between provings but it takes a lot of time to make).
I leave my starter out of the fridge overnight, Friday, make a leaven the following morning, Saturday and leave it 9 to 11 hours to rise.
Mix the flour, water and salt; knead 20 to 30 mins by hand or use a mixer.
Leave in mixing bowl covered with cling film between 3.5 and 4 hours to rise.
Knock it back then place in a floured banneton and leave in the fridge overnight and cook Sunday morning. No tea towel required.
Sugar, or honey, is added to make the crust firmer but I can't tell the difference so don't use any.
Took me a year to get the knack and even gave up for a while because my dough was really sticky and I didn't know what to do. Keep at it because it's rewarding. My mate's rosemary and sea salt focaccia is to die for, especially with olive tapenade.