...So how do you guys go about developing your investment strategy,..

Lots of reading and posting on boards like this. I find that answering questions that I know(or think that I know) something about makes me think through the investing process and helps me understand things better. This includes understanding the point of view of people who disagree with my ideas and sometimes learning enough to change my mind about how something works. My standard recommendations for books are “the Bogelheads investing guide” and “The four pillars of investing”

One of the things that I have learned is that there are really only a few things that you can control well. These are;

1) How much you save or spend each year.
2) Keeping taxes and costs low.(this is the biggie)
3) Your asset allocation.

Things like being able to time the market or pick the next hot stock might be possible but the odds of an individual being able to do it well over several decades are minuscule. This pretty much leads to index funds for the bulk of retirement investing.

Greg