In this 7 part video series, tickertank.com founder Nick Fenton explains his criteria for selling Naked Puts (short puts). Part 3 discusses time preferences for entering Naked Puts, as well as some loose rules regarding timing the exit.  

Keep in mind this criteria is specific to Nick, and is the result of several years of trading this strategy. Nick’s criteria may not be right for you, but worst case you get a look over the shoulder of an expert.