One of my favorites methods includes using a shoe string or something of that length. Tie a loop in one end, tie it so that you can slide the knot to make the loop smaller. Slip the loop over your dick and balls and then tighten the loop down tight but not painfully so. (Do not leave this on for more than 15-20 minutes.)
Throw the other end of the string around the back or your neck and let the loose end hang down your chest.
Now, when you start stroking, pull gently on the loose end to put pressure against your package pulling it up.
Really hightens the orgasm.