Stretching consists of attaching a penis stretcher or "extender" device to the penis for set periods of time. The device exerts a constant traction on the penis, which, in theory, lengthens and widens the penis. The traction supposedly causes the cells in the penis to divide and expand. In 2002 a study published in the International Journal of Impotence Research concluded that penis extender devices are effective at elongating the penis and furthermore the increases in length correlate with the amount of time the device is worn. A study conducted at the University of Turin and published in 2009 in the British Journal of Urology showed similar results, using a penile extender exerting a continuous and gradually increasing traction force on the penis. The device consists of a plastic ring, where the penis is introduced, with two dynamic metallic rods which produce the traction. After using the device at least 4 h daily for 6 months, the mean gain in length in flaccid state was 2.3 cm, with significantly improved erectile function scores and treatment satisfaction scores of "acceptable" to "good improvement" in all items, except for penile girth, where there was no significant measurable or subjective changes. However, the study population only included patients with inadequate penile dimensions, so it remains uncertain whether people with usual dimensions would have the same effects.
I've never used one - but who knows - maybe you could do more research on these two medical journal reports.
There seems to be some risk in all of the methods - so good advice above - be happy with what you have. I get a lot more sex because of my small size from top guys that like to get f*cked from time to time that I lose sex from size queens.