i agree pretty much with Miffed22001 although for the JJ/TT call i am looking at texture as well as overcard situation. with those you have to assume you are even money or worse to see an overcard, but even low money flops (6-7-8, 3 suited, etc.) can be problematic. betting patterns and your reads take you from there. although you only asked about PF action i think...

mulligan