It's very simple. Vote for the thread's discussion content for the month. If you post here, only talk about whatever topic is in the lead. Don't talk about what you'd like to see win, just discuss what's winning. Try not even to mention the OP or the other options.
Send me suggestions for next month, but these are the one's for Jan.
IN CASE OF A TIE
try to make each post relate to both subjects. Have fun