I've only had 1 atti go bad in 3 months (knock on wood), so my observations may be of limited use here.
I did have two come DOA 2 months ago though. (I believe they were a Dse103 and M Series)
I just do regular maintenance on all that I use.
Depending on the atti...
Steam Cleaning, Cola Soak, Alcohol Soak, Ultrasound Soak, Distilled Water Soak, Burn Off, etc.. I'm sure you've read about all the methods before so I won't bore you, but find one you like that works for you and stick with it regularly.
Hope you have better luck with atomizers in the future!