Seasonality is a great tool that can be combined with other forms of technical analysis. In this video Tom demonstrates how to use the seasonality tool on StockCharts and how seasonality looks on a chart.
Volume by Price is an overlay you can add to your chart. It places volume bars behind the price, allowing you to quickly visualize possible support and resistance areas.
A cool feature of StockCharts is the ability to add an overlay to an indicator; such as a moving average on the RSI, or a horizontal line on the SCTR. Greg shows you how to set it up, including changing colors.
Relative Rotation Graphs can be used very effectively to drill down from higher levels on the asset allocation pyramid and then to individual stocks. Julius de Kempenaer, creator of the Relative Rotation Graph, shows you how.