Moving averages can be used in allot of ways effectively. They can be used to determine Reversals, ie golden cross and death cross. Your time frame and trading style should dictate the length of the averages you use whether it's 20/50, 50/200 or custom. ie If you short term trade and hold a position a week - 2 months you should use shorter term avgs; if you are more of an investor then the 50/200 may be more suitable.If You Trade Using Moving Averages, How?
Moving Averages can be used to determine Direction and Strength of trend. ie In an uptrend the shorter average will be above the longer average and price will be above both averages. When the width between the two averages expands the trend is getting stronger; conversely when the width is shrinking the trend maybe getting exhausted.
Likewise you can use averages for effectively identifying good Entry and Exit Points. ie If looking to enter a trade (uptrend) and you see price trading way above the short term average (topping or above normal top) you should anticipate a pullback in price, a reversion to the mean; compare to Overbought conditions. You may want to wait to get long or if already in a long position, you may consider taking profits. Conversely, if price drops below averages you may want to cut losses.
Averages can also be used to see what Stage a trend is in, whether it's in its beginning stage or somewhere in the middle or possibly near the end. Trends have Legs which is drawn by the averages thru expansion and contraction, and a good long trend may have 3 or 4 legs before maybe getting near Exhaustion and possible Reversal or Sideways market (consolidation). In a consolidating market averages become moot. Keep in mind when a market consolidates that means buyers and sellers are uncertain of future direction, there is a pause. The longer the consolidation usually means a more wound up market, thus a bigger breakout one way or the other!
Finally, moving averages are used as Support and Resistance. In addition to horizontal S&R levels. ie In an uptrend price will have a tendency to pull back to the average and Bounce off it or the average may play catch up to the price.
In conclusion, you should always be aware of where price is in relation to the moving averages and the historical patterns and tendencies of the stock or indice you are trading. Learn the animal and what makes it tick! All holds true likewise in down markets (down trend) but obviously flip-flopped.