The BIG CLUE that everyone has been guessing for on s06e01 is basically the title itself. 'Desert Rose'. It basically has no meaning cause rose doesn't exist in desert. The murder in the first episode took place in a desert. That's the link to desert but the link to rose is pretty much obvious. Rose is red. Red is Red John. He loves patrick so rose in dessert is basically red john in dessert which i'm indirectly saying that patridge is red john. 

Don't judge a book by its cover but judge it by its title. 

I admit this is a bullshit theory and you will probably click unlikely, im terribly sorry for making you think like that, cheers.