Foreskin Twist
This technique only works if you have your foreskin but believe me it is mindblowing. First lie on your back and get a good hard on, I mean a big stiff one. Then put some lube just on the head of your penis, then with your foreskin over the head of your penis twist it back and forth occasionally going up and down. If you lift your pelvis while doing it, it increases the sensation. Believe me it may take about 20min to cum, but you'll enjoy every mindblowing moment.