1) Stock Strike Price must be at least 10% lower than the current price.
2) Strike price must be closer to solid support, so that if assigned can ride it out!
3) Stay away from high-BETA stocks.
4) No matter what, don't sell a put before the underlying(stock) earnings(or for that matter, any catalyst) are due!
5) Wait for a catalyst to happen before doing a sell put "OR" look for stock candidates that had some kind of catalyst as recently as possible.
6) Cover (liquidate) profit position if premium falls by half very quickly, i.e, in a week
7) Make a mental stop-loss and stick to it religiously.
8) If assigned, do a DTM covered call and get rid of it as there are many other opportunities waiting by.