I am a firm believer in tracking all your stock trades. In fact, you can see how all my trading strategies are performing by visiting my trading profits page. By tracking your trades according to which strategy you are using you can identify how profitable a strategy is and whether you should be using more or less money to trade it. Furthermore, tracking your trades will help you to avoid trades that are based on hunches and not on specific strategies, because it will quickly become clear how quickly you lose money on such trades.
Download below a version of the trade log spreadsheet I use. Use a separate sheet in the spreadsheet for each different trading strategy. Watch the video below if you need guidance in how to use the spreadsheet.
[Edit 2013-12-3]: I created a new version that has separate columns for commissions because some people find this to be simpler (I just use formulas to include them in the trade price) and I saved this in the current Excel format. Download here.
[Edit 2015-3-24]: I finally uploaded a version to Google Docs and improved the formulas. Go to “File” > “Make a copy” to save a copy to your Google Docs so you can edit it.
Disclosure: No positions in any stocks shown in the spreadsheets or in the video.