I consider alot of things

number of opponents
type of opponents
texture of flop (is it likely to have helped anyone?)
do I have outs / backdoor outs?
potsize? (people tend to give up small pots easier)
position of opponents (and do they always check to me regardless of whether they have hit or not?)
my image
Have I actually hit my hand??

and so on...

The more experience you get the more things you start to think about here.