Flush Draws

[calidist]

Hi All. Long time reader, first time poster. Primarily play low to mid stakes on party.

I was curious what you all think about flush draws on later streets (6th and river) when you have four to the flush. This hands are particularly hard for me to play. What do you all consider when you are in this position and what guidelines do you use? Specifically, how many cards of the suit need to be live and what are the pot odds you need to confidently call on 6th?

Thanks a lot for your thoughts.