My plan is to invest, rather than trade, although this depends on how you define these. Somewhere it was described to me that trading is trying to capture volitility in the markets and use it to your advantage, whereas investing is diversifying your money and believing that over the long term the market as a whole will rise (but not actually buying or selling actively). So my strategy would fall somewhere between these - buying low and selling high but doing so over a long time frame (every 6 months or year).
I have been doing some research. I've attached a graph that I created in excel of the log of the share price for XJO from December 1979 to November this year (data from asx.com.au and economagic.com, data is end of month values for XJO from Dec 1979 to Nov 2008 - if anyone knows where I can access data prior to 1979 I would be interested). As I'm sure many of you are aware the rise in share price for this index fits an exponential function (linear if using log values) fairly well (R-squared = 0.93). The variations about this line of best fit are what interest me. If it could be assumed that the share price will continue to follow this general trend in the future (which of course is a big assumption), then the variation of its price around this trend line could be used to your advantage. During periods where the trend is lower than predicted (the market is under-valued), one could buy into the market (perhaps waiting for a small rise or long flat before doing so), and vice versa - sell when the market appears to be significantly over-valued (or at least keep a keen eye on the world economy and pull out if there is indication of a coming bust - something I'm sure we all wished we had done / are glad we did last November).
This is not financial advice, merely a historical analsysis, so dont sue me.