Tips for cumming prematurely

Is there any extreme efficient way to become a premature ejaculator? I tried clenching and the one finger method but I'm always too impatient to pull through, please help me if you have any tips and tricks, I tried cumming to censored porn and felt like nothing changed although it's Still hot and I still goon to it, I don't have a chastity cage or a vibrator but I will do what I must to become a premie, should I only stick to censored porn? Please help I don't care how extreme the method is as long as it's effecient