At a family gathering this weekend I was happy to discover that a cousin-in-law of mine also likes to bake. It was great to get caught-up with him and to trade tips and techniques for the art.
One of the items that I mentioned was that there are quite a few non-recipe variables in-play with bread making that you have to keep in-mind:
1) kitchen temperature
2) water temperature
3) rise times
4) "liveliness" of the yeast (though this one is hard to measure) or amount of yeast (easier to quantify)
I recommended to him that if you keep the tempatures and times roughtly the same each week the one variable that is key to isolate and experiment is the liveliness of the yeast. It's isually best to adjust the amounts of starter you use each week and then subjectively score how the loaves turn out.
We are in the process of moving so this is the first loaf I've done in weeks. Not the prettiest, but I certainly like the energetic rise of the local sourdough flora.
One of my best friends has turned me onto a fascinating on bread baking. I've probably seen at least 100 books on bread and very few of them have impressed me, but this one has proven to be different. I highly encourage you get a copy and take a look for yourself. I'll have more to say about it in the future.