Mental tricks with long odds

[J_V]

I have a question about how to estimate "probability of being good" or the probability of winning the pot via bluff. These skills are very important in limit poker but are very unscientific. What are some tricks people use. For instance its sort've hard to appreciate what 1/10 is. Often times people get discouraged bluffing, when it fails a high %, eventhough it may be profitable in the long run. It's hard to estimate if a play is profitable against a player if you bluff once a month and it only has to work 1 in 10. What I try to do is put myself in their shoes so I can guage how often I would fold. Of course this is not all that effective. As SKP says, "It's easier read a players hand, then his mind." Maybe, I am asking the impossible. Any other ideas?