This technique works extremely well for someone who has no trouble with an erection but, perhaps through age, is finding ejaculation more demanding. It can be carried out either dry with talc, for maximum sensitivity, or with lubrication. (Soap and water is brilliant).
Circle the penis with one finger and thumb immediately below the head. Jerk finger and thumb, keeping a neat circle, forwards and backwards over the ridge at the base of the head. Each movement is no more than an inch each way. The effect is very powerful and can achieve maximum stimulation with the desired outcome.
Pleasurable variation is afforded through changing hands, changing the direction fingers point and changing speed or pressure.