Hi Dale, nice to bump into you again!
I now use MA crossovers (only 8 and 21 EMAs) as my primary trading system and even commissioned my own EA. My trading system is as Dale suggests - wait for a crossover, wait for a pullback and then make an entry decision. I use a two-bar pullback or an IB setup with stop orders (not limit orders) to help me identify a “pullback” or hesitation in the trend. The SL goes on the “wrong” side of the mother bar or of the second (pullback) bar, or further away based on price action, as you wish. From April to mid-December last year I made 78% return just like this.
My (mostly manual) EA that I have more recently started using sends a signal when there is a crossover and then I have a good look at what’s going on. If it seems good, I click “Go” to switch the EA on and it tracks the fast MA with a limit order until the order is triggered. Exits can be by a fixed number of pips or at the next crossover. Entries should preferably be fairly soon after the crossover, not once the trend gets a bit old and tired, in fact not even after it shows signs of middle-aged wobbles. Stops can be by a fixed number of pips or if the MAs cross the wrong way.
There are some safety rules when using MA crossovers, for example, don’t trade into an S/R level or towards an extreme level. Also, if it looks as if price is consolidating or entering a range, be more cautious. If price has pulled away from the MAs and left a bit of an open space between price and the EMAs then it is likely that price will bounce back across the MAs and stop you out (the elastic band idea), so I prefer a period of shorter candles that creep along fairly close to the MAs. I can also use my EA to move to B/E at a certain number of pips, or to trail the stop, but I don’t usually use trailing stops.
So you’ll see that my EA is hardly a trading robot - rather just an automated entry and exit tool that relies on the trader’s careful consideration.
Generally, then, and used too trustingly, MA crossovers will destroy your account, but used carefully and while observing certain rules, they are very useful.