5. Time to expiration - as part of my credit put spread strategy i consider how long i have until options expiration. The markets have had greater price swings last few years than normal, ie your stocks move around more. so realizing this will happen, i usually select the front month for my credit put spreads and almost never use weekly options for credit spreads. I enter a spread with the assumption that i have not picked the bottom. That the stock will move around a bit after i enter. By picking an expiration with a few weeks to go i reduce my stress (i have time for it to recover if it drops vs freaking out if i put on a weekly spread and stock moves against me).
The reason i dont pick an expiration month a few months away is that the nearer dated month will have more time decay than further dated. The best case when entering a spread is that the stock makes an upward move, ie your spread decreases in value (you profit).. so if that happens a front month spread will profit more than a further dated spread. So front month spreads give me two advantages.. better profits on an up move and better time decay. Additionally, going out several months you start getting involved with earnings dates.
Now you could sell weekly spreads because of the quick time decay and you will have some profitable trades. But in order to get any decent premium i would have to have strikes closer to at the money (the 20delta on weekly is not the same delta on monthly). So going closer to ATM means higher likelyhood that stock moves against me. Having the strikes far enough away (20delta) allows for the greater swings of the stock, so for my style weekly options negate that. You could have an event happen where your thesis is a quick reversal or flat (ie, picking the bottom).. Such has earnings selloff, rumor, stock down big in sympathy to some other stock, etc.. then maybe you can do a weekly spread. But then again if you enter a monthly spread with few weeks to go AND you have successfully picked the bottom, the monthly will also profit to a lesser amount.
I also like the flexiblity of being able to make the spread into an iron condor if needed if the stock moves against me. Its your call though, if you feel comfortable with the risk / reward of selling weekly spreads then knock yourself out. I'm just sharing what im comfortable with and what has worked using my system