Just MHO, but I don't believe a sourdough should be more than very slightly sour (the 'sour' in the name refers to the starter, not to the loaf).

It's also worth experimenting with different recipes for different styles of loaf. All down to preference, really - if you like sourdough bread to have an open texture (rather like ciabatta) you obviously need a looser dough. Thing is, that makes the dough significantly harder to work with, especially if you're doing it manually.

It's also worth researching stretch & fold and boule-forming techniques if that's something you don't do with poolish methods (it's more important with sourdough). The former gives (IME) much better results when you're knocking back than either just tapping or kneading - that little extra texture in the dough. The latter is key if you want a non-tin loaf - you seriously need to get that surface tension to keep the dough in the right shape (even with a proving basket). Gives a better crust, too...