I use ATR a lot when designing trading strategies, this way the strategy adjusts to the instrument in most cases instead of me plugging in special numbers.
However, ATR itself could get spiked by some violent moves. For this I have created MinATR which I am publishing here.
It is effectively ATR + minimum ATR over the last "Min Length" bars. (this is a parameter which I have defaulted to 50).
So use this the same way you use ATR, but it will also show the min ATR over the last "Min Length" periods.