I use the 20-bar EMA on the daily chart for larger S/R levels. For example today the ES should sell off if it failed to break through 1190. Indeed there was a nice reversal off 1189.75.
I use the 20 EMA on the 5-min charts for entries with a trend (enter when support or resistance is established at a rising or falling 20). In a strong trend price rarely pulls back to the 20, so I then cross-reference a 3-min chart and use the 20 on that chart for entries. For example, say you sat at your platform around 7:30 ET this morning and wanted to join the uptrend in CL at a good price. Normally you'd wait for price to pull back to the rising 20-bar EMA and buy there. But you can see that the pullbacks are very shallow, so if you cross-reference the 3-min chart, you get a long entry signal right around 7:54am when support is established at the 20 EMA in that time frame. In very strong trends you can jump right in anywhere, like I did yesterday with ES as it was selling off. Screw the EMA's, I'm jumping off the cliff with all the other lemmings, and asking questions later
When a trend has been on for a while and looks overextended you can counter-trend trade (I do that sometimes), wait for the lower high/higher low or DT/DB (I do that more often), or if you're very conservative wait for the first bar that closes above/below the 20 EMA counter to the previous trend. So this morning on a 5-min chart of CL, the 9:40am bar closed below the 20. When the following bar fails to break through that previous bar's high, you have a fully confirmed short signal (lower highs and break of trend).
It's more like training wheels for me than anything else, mainly because so many traders follow it, it becomes a self-fulfilling prophecy.
)