From the replies in this thread I've decided to make a sourdough starter and in the process found out that my yeast was coming into contact with my salt. I know put my yeast in before the flour. Much better results now that I have formed a barrier between the two.
I still like to start a sourdough starter with a sourdough starter, not just commercial yeast, I think a lot of the commercial baking yeast are highly aggressive, and leave out some of the sympathetic bacteria that make a sourdough starter sour.
Have at times had several starters going at once, so if you don't want to use say the 1847 starter, or King Arthur Flour's starter, and just want to make one from scratch, it just takes a little longer. You'll need a 2 quart container.
Then do this, real easy, just be prepared if it doesn't work the first time, if you get something that smells foul, is orange or green, it didn't work.
I'd start out with 1/2 cup flour and 1/4 cup non-chlorinated water. You'll need a 2 quart container that should be covered, but not airtight. A porcelain crock works great.
Work on this for six days, each day adding 1/2 cup flour, 1/4 cup water.
You should be getting something here that is about two cups, yeasty and bubbling. Use a cup in most recipes, replace it with the same proportion of water and flour, let it sit for a couple hours, if this goes in the fridge, it goes quiet, has to be woken up, dump off a cup, replace with 1 cup flour and 1/2 cup water and let develop for several hours.
Depending on what flour you use and your environment, there will be natural yeasts available or not. If you are having trouble, I'd suggest starting with a particular starter from a friend or from KAF or 1847 as above, I'll also be happy to send you a 1/4 cup of mine.
If you get mold, things have gone wrong. Sterilize, start again.
The longer you keep a starter going, the more complex and interesting it gets, that is because it accumulates local yeasts, but also helpful friendly bacteria that make that sour taste. There are often not so friendly bacteria, but you can tell if they move in by the orange tint and bad smell. Our yeast friends will kill the heck out of them 95% of the time.
It is kind of funny as if you move, your bread will suck for about two weeks, it will work, but not be as good as it was. That is because there is a yeast and bacteria battle going on in the starter. They eventually sort out their differences and make the bread even better.
TBS